I've been stalling on doing 474 because the sound effect in panel 4 I can't understand and have been unable to find in dictionaries. I've been telling myself that I'll ask some native speakers about it, but I keep forgetting... and who knows when I'll stop forgetting, so I'm going to totally invent something based on context, and if I get around to discovering its real meaning, I'll get back to you. update: helped out by iheartmcz got this nailed down.
#474
Spoiler:
title} Oni Island (11)
1} A: Congratulations on making it this far Momotaro...!!
2} A: You wanted to meet A-rin this badly...
3} A: Your clothes aren't pink!! (smaller) even though you're named Momotaro! (tr: We all know that "momoiro" is pink, right? ... Same "momo")
4} A: You... got some grit...!! (background) angry smile (tr: also considered calling it "cold rage" or "hidden rage," if you want to choose one of the other ones, go for it, or actually anything else you think of?)
#475
Spoiler:
title} Oni-island (12)
1} (panel): Oni-Boss A-rin has appeared!
2} A: 1 vs. 4, no fair A: Oh yeah!
3} (panel): A-rin called allies! A: Heeeey
4} (panel): But wait! Large numbers of A-rin loving Kohai assembled!! (background): lined up
And in another story of my stalling, when I read 475 I needed a breather because assembling A-rin's kouhai includes Ebi-Chuu.
2} (panel) But wait! A-rin transformed!! (background) Baaang
3} (panel) A-rin's HP increased! A-rin's MP increased! A-rin's attack power has increased! A-rin's defense power has increased! A-rin's pressure has increased!
A: By the way, there's still...
4} A: 7 more transformations ♡ (background) Boooooom
I honestly have no idea! For whatever reason it's totally slipped through the cracks of anything I've seen or heard before. I don't have a refined ear for Japanese onomatopoeia, but if biki biki is anger, it would strike me as the pulsating vein, which is not what was drawn. But just the same, I also read into the scene that she was smiling over anger.
Okay, just searched again for 2ch usage, and came up with... it's the sound of exactly this scene. Weird. It's smiling with your vein bulging. Thanks for the renewed motivation and direction iheartmcz! http://dic.nicovideo.jp/a/(%23%5E%CF%89%5E)%E3%83%93%E3%82%AD%E3%83%93%E3%82%AD
Lazy bum that I am, I'm definitely in no place to complain about delays.
#478
Spoiler:
title} Oni Island (15)
1} (panel): Due to the intense pressure of A-rin World, Momotaro...
2} (Happi coat right side) Pichi Pich desho! (Happi coat left side) sexy de Ochame (tr: I assume everybody recognizes A-rin's self-intro; parts are covered by the towel and not transliterated here)
3} (panel) ... entirely converted to A-rin Oshi (background) Urya! Urya! (tr: the downbeat part of "Urya-OI! Orya-OI!")