[DreadBringer]

Kanna seems to be set up as a red herring for this case, due to her not showing up at the gathering (which can imply she's acting as Alcohol Dopant somewhere else), her denial when being interrogated (often done to hide their actions), other brides being killed with Kurumi being surprised (thus she doesn't know why Kei was killed and by extension Alcohol Memory). But turns out that in this case, all of them are technically Alcohol Dopants. Though there are bitchy brides particularly Kei, the culprit here wouldn't be any of those, the brides are guinea pigs, and they die by using said Memory, with Philip not lying when he "saves" Kurumi from certain death.

Finally Shotaro did it, actually recognizing in-universe that his idealistic beliefs can have him being looked down by others as 'half-boiled', though fortunately for him here, Philip actually praises this trait of him that it makes Shotaro a good judge of character instead. Other than Shotaro perceiving Kanna's hospitality as genuine that murdering others is contradictory to her inability to abandon others or her plea at the night, I agree that it'd be unnecessary for her to save those 2 when she plans the murders. So once in a while, W had a genuinely good-natured hot girl in Kanna, with her actually forgetting the events too by being KOed when trying Alcohol Memory (and probably missed the gathering due to being unconscious).

Philip's pretty boy looks is used in an important manner again... as a crossdresser to get to know the Alcohol Dopant users (all 4 brides). By disguising as Kanna, Kurumi exposes the truth behind Alcohol Memory out of her jealousy and competitiveness (more with Kanna being perceived as Kuya's favorite).

Tokime's Fuuto PI audience surrogate as this is the sequel of W, and thus she'd have over the top reaction when turns out that what Akiko wrote was literal, Accel really is the bike. Have looked forward into her reaction knowing this, and t's priceless, and even some audience do have a reaction as surprised as Tokime learning Accel is a bike.