what

who

maybe this is the sister that she injected juice into

She looks like the big sister then, unless the big sister/little sister dynamic is like Tenma and Yakumo.

Fanart already? Great.

was gonna say that they reminded me of tenma and yakumo tho without yakumo's distinctive eyes and tenma's antennae.

Yeah the sister definitely look like a cross between yakumo from school rumble and sasaki from azumanga

"Whump" comes to mind.

I'd like to inject into her if you know what I mean.