Getting a kogal sex friend (upgrade to girlfriend) who can be Violently Protective if or when required - especially if you stood up for her - Keita-kun, you've scored the SUPER JACKPOT ... you Lucky Bastard (grr).
The chemical reaction that creates some sweet, sweet Vanilla...
I have to say this protagonist is quite the nice guy though. He agrees to help teach a girl he just met, and when she was being bothered by some guy, he stood up to him.
Also, "Through some sort of miracle"? It was no miracle at all, because sex in Hentai solves just about every problem, and that includes tests and studies.
That ending though. I suppose the correct reply would have been "I'll tutor you to make sure that happens", or something?
All about chemistry
Won't you show me everything you know
Ah wonder what you do to me
Oh-oh-oh-oh-oh, oh
All about chemistry
Won't you show me everything you've learned
I'll memorize everything you do to me so I can
Teach it when it comes my turn
Mhmm... the only song with "chemical" popping into my head right now is this one:
Walking on the foggy shore
Watch the waves come rolling home
Through the veil of pale moonlight
My shadow stretches out its hand
And so we lay, we lay in the same grave
Our chemical wedding day