Not posting scans/images from the book, but I’ll include reference images from the game websites. I’m pretty sure some of this is already floating around on the internet, but figured I’d put together something comprehensive.

There’s an interview in this but it’s 12 pages long, so… later.

P.S. Why is the cover so slippery? It keeps sliding off when I let go of the book to type ;_;

Click images for bigger version.

P3D – Stage Costumes

	He doesn’t have much of a strong personality compared to other protagonists, so it was difficult to come up with a unique fashion style for him. Also, if we focused on his personal colour, blue, then it’d be cool colours from top to bottom which would make him seem like less of a protagonist. After deliberating, I found that a metallic silver top would have an interesting texture despite being colourless. It had good design sense while also expressing P3’s “city life” and “cyber” aspects! (Kabayashi)
	There wasn’t really any doubt about Sanada’s design. I figured that a boxer should have a hood, so I gave him one and brought out his manly stoicism. I considered making him look sillier because of the recurring gags revolving around him, but in the end, my desire to see him looking cool won out. (Kabayashi)
	The theme was simply “cosmo.” Since he’s the liveliest member of the P3 cast, I thought he’d be the only one who’d wear a patterned shirt that packs a punch, and gave him a flashy design as such. I figured that out of the male cast, he’d be the most conscious of being popular with the ladies, so he’d try to look cool by casually wearing his blazer around his waist in hopes that girls would admire him… That’s what I imagined while designing him. (Kabayashi)
	Out of all of the boys’ stage costumes, this was the one that strayed the most. At first I considered doing something unexpected by making him look like a little brat, but it didn’t work out. There wasn’t anything interesting about just making him wear a shirt either, so I came up with the idea to add Koromaru-related elements–which was a good idea, but I didn’t know how far to go with it, and in addition to the wings on his back I even gave him paw-shaped gloves. It got rejected because it was painful to look at. (Kabayashi)
	The original design had her wearing something like a custom-made jacket, but it was rejected because she looked like “an emcee at a show.” I thought that Yukari was the type of character who would be reluctant at first, but still agree to show off some skin, so I shifted to a fresh, seductive look. The design itself is a typical dancer’s tank top + off-shoulder shirt combo, but I made it out of vinyl to match the protagonist’s expression of P3’s futuristic style. (Kabayashi)
	Fuuka was the easiest out of the P3 girls. She got an oversized sweatshirt to show off her dainty girlish-ness and coloured tights that suit the liveliness of a dancing game while not being revealing. Unlike the other characters, her headphones have a subdued, realistic design. This is because I thought Fuuka would be picky with her gadgets since she’s good with machines. (Kabayashi)
	Her theme was “plays a male role in the Takarazuka Revue (an all-female musical theatre troupe).” At first I had Mitsuru wearing a skirt like the other girls, but it really didn’t suit her. Thinking about it now, a mini-skirt is a bad match for a mature woman like her. So, I tried changing it to pants to emphasize her aura of an imposing commander, and it was surprisingly fitting, so I continued with that. By the way, her open chest is for fanservice. (Kabayashi)
	A near-future design with glowing headphones and shoulder parts was the plan from the very beginning, but those alone weren’t much of a change compared to the other characters. Somewhere along the way I put her in a dress, thinking that it wouldn’t be used, but it was unexpectedly well-received, and they said we would go with that. By changing her characteristic red ribbon to light blue, it’s like discovering a new side to Aigis’s charm. It turned out to be an unexpectedly amazing design for me. (Kabayashi)

P3D – Halloween Costumes

	Pumpkin-themed Clown Suit I gave him a clown costume because of his ties to the “Fool” tarot card. My colleagues watched over me out of concern that a clown costume might be disturbing, and when I added the red nose, it was surprisingly fitting for our protagonist. (Oribe)
	Full Bodysuit and Bandages Junpei had to pay for the girls’ costumes, and in order to save money, he became a mummy because it could be done with just bandages… or so the story goes. Most of his face is covered up, but he’ll hang on to his trademark cap until death. (Oribe)
	Exorcist’s Robe It took a lot of effort to decide on the theme for this costume. At first I was going to make it something from a horror movie, like Jason or Freddy, but scrapped that idea because it was hard to convey. I also tried putting him in a Reaper costume, but in the end I settled for an exorcist. (Oribe)
	Pumpkin Costume Amada always gets put into cute outfits, so this time I was going to give him a cool Dracula costume. However, it was already being worn by a certain ringleader ((Yuu’s costume in P4D)), so he regrettably became a little pumpkin fairy instead. (Oribe)
	Zombie Nurse Costume Yukari’s costume was decided on fairly swiftly–a zombie nurse for our resident expert in healing spells. I also thought she’d be willing to keep one of the chest buttons undone. (Oribe)
	Tin Suit Since she’s a robot, I themed her costume after a broken-down toy. At first I thought it was too ironic and would only elicit pity, but Aigis would take a questionable joke seriously… so I went ahead with that joke. (Oribe)
	Witch Dress A typical witch that you’d expect to see holding an apple. Her long dress was rejected because it was too difficult to apply the animations, but adding a long slit made it OK. (Oribe)
	Spiderweb Dress Nothing came to mind right away, so I tried different designs like a mermaid, snow maiden, mad scientist, etc. In the end, I settled for a cute, normal Halloween-themed dress. (Oribe)

P5D – Stage Costumes

	Even though I designed him first, I couldn’t settle on a colour for his shirt until the very end. That said, when you’re creating designs like this, you get characters competing with each other for dominant colours. In this case, there were three colours that would suit the protagonist: white, black, and gray. Morgana got white and Makoto got gray, so I gave the protagonist black. (Kabayashi)
	For Yusuke, I definitely wanted to dress him in something silly that his friends and the players would poke fun at, but I also wanted it to be a costume that could be considered cool. So, I used a leather jacket to secure the “coolness” and stuck gaudy spikes all over it, which had the additional advantage of an avant-garde look. I designed him while imagining him approaching his friends with a “Behold, this avant-garde design!” look on his face, only to bump into someone who retorts with an angry “Ouch!” (Kabayashi)
	Ryuji can’t stray from his rowdy character, so his costume was easily decided. He got a bandana with a street gang-inspired skull design, gold accessories, and shoes that are more like sneakers than dance shoes. His ensemble emphasizes his existing personality. (Kabayashi)
	Morgana has the same role as Teddie from the previous game, so I considered how to transform him as the logo for the game. Since Morgana loves treasure, I knew I had to give him a crown, turning him into a dance king. (Kabayashi)
	I wasn’t sure how to design her since she looks good in everything (which is a good thing!), but I ended up giving her a “bad girl” theme. Extra attention was given to the granularity of her tights. If the gaps were too big they’d become fishnets, but if they were too small then they’d be indistinguishable from regular tights, so I had to search for the perfect size. (Kabayashi)
	Her design deviated the most out of all of the P5 characters. P5 as a whole uses the colour red and I used a street/”dirty” style for these designs, but Makoto herself has the opposite characteristics–she’s a “serious” type and her personality is represented with cool colours. So, I wasn’t sure whether I should prioritize the street style or her personality, and in the end I didn’t do either–I went for a “decadent champion” theme. (Kabayashi)
	Futaba doesn’t wear a school uniform to begin with, so if I changed her clothes too much, it could stray too far from her original look. So, I added things to her clothes without changing her fundamental appearance. Since she has stickers on her PC, I added crests to her jacket that she would like. I wanted her to enjoy the festivities in her own way. (Kabayashi)
	Haru is a prim and proper character, so just like with Makoto, street style didn’t suit her either. I definitely had to have the ballet-themed corset and puffy sleeves, so I figured I would try a gothic theme and it ended up being a great combination. Strictly speaking, it’s not street-style, but I don’t think she looks out of place with the rest of the characters. It’s actually my favourite design in this game, and I know it doesn’t mean much coming from me, but it’s so cute… (Kabayashi)

P5D – Halloween Costumes

	Great Magician’s Robe Though the protagonist dons the robe with style, I ruined it with comedic accessories. A magician has to have a black cat, after all! There’s a crafty Morgana doll hiding in his waist pouch ((you can’t see it in this image because it’s on the back)) and I gave him a brooch with “J” for Joker. (Shimada)
	Pirate Coat He’s a pirate captain, following from his Persona. I wanted to make it more Halloween-y, so I gave him a skeleton pattern on his undershirt and glove, a spiderweb on his hat, and made his robe all tattered, so that he would look more like the captain of a ghost ship. As for the mustache, I was sure that Ryuji would happily wear it, so it adds to his festive personality. (Shimada)
	Vengeful Attire I tried a lot of things like a defeated warrior or a jiangshi, but in the end I settled for a simple approach: traditional Japan x monster = Japanese-style ghost. At first I asked if they could use special effects to have the fireballs fly around, but we stopped because we were afraid it’d look too unsettling *laughs*. In the end I decided to make them look like he’d handmade them with cardboard and springs. (Shimada)
	Worn-out Cloth & Pointy Hat I thought it’d be cute for Morgana to look like a teru teru bouzu, so his was decided fairly easily. He has a big cloth draped over his head, held in place by a ribbon and tie wrapped around his neck. I made his tongue stick out so that it’d look like he was going to play a prank on someone, and it ended up looking really cute in 3D because it would sway around as he moved. (Shimada)
	Succubus Dress Ann looks incredibly mature when she lets down her hair, so I thought I’d design something really sexy and cute to go with it. I used heart and bat motifs–I love the heart pattern going down her tights. Also, by facing the two bat wings on her skirt towards each other, it forms a heart shape there too! I added them to both the front and the back when I realized that, and I secretly love that part a lot, too. (Shimada)
	Candy Dress I crammed a ton of decorations in because a rich girl would be able to special-order a fancy outfit. It was fun to design because it involved drawing a lot of cute, colourful sweets. The pastel colours bring out Haru’s personality too, while her hat has a poisonous-looking purple cream dripping down from it and a scowling pumpkin lollipop. It’s got some eccentric features. (Shimada)
	Zombie Cop Costume This was a fairly straight-forward decision, because police costumes are standard Halloween fare and Makoto wants to join the police force. Her black gloves and boots give off a punk impression that suits her well. I used high-saturation colours for the zombie makeup so that it wouldn’t look realistic. (Shimada)
	Alien & Laser Beam Gun Futaba seems like she’d love to wear a monster costume, so I gave her an alien costume because of Necronomicon. It may look simple, but I struggled a lot with the face. I couldn’t make it too gross or too cute… It felt like I was walking on a tightrope *laughs*. As far as mechanical elements go, I tried giving her things like a small UFO or machine, but I ended up going with a suspicious collar and a laser beam gun. (Shimada)