Imagine Tousuke but it's the Mixed Messages/Red Flags duo.
Like pleaseeee it would be so funny. If we're going by vibes I'd put Kusuke as Mr Mixed Messages and Akechi as the Red Flags girl, but also I think Kusuke is the type of freak to be into The Human Centipede so it could work both ways.
Also if Akechi was the Mixed Messages guy it would mean that he gets to punch Kuniharu in the dick which would be really funny. I don't know who I'd substitute for the "dad" if it were the other way around.
After some thought, I'd still go with my first instinct. The characters just fit better with Kusuke as the Mixed Messages bastard and Akechi being the freaky off-putting one who allows Kusuke to "finally open himself up to love" lmao. Akechi doesn't give me mixed messages vibes at all, but Kusuke absolutely does.