The reclusive bottom starts out straight, but the top's tenderness proves too much for him to resist... He goes from straight to gay.
School bully top, aloof academic genius top, ghost top, fairy-tale top, doctor top, monster top...
The school bully top bullies him.
The aloof genius top likes to trip him up (he wants the bottom to pay more attention to him, but is too embarrassed to say so).
The ghost top wants to find a "mother" for his children (at first he pretends to be a helpful citizen and tricks the bottom into coming home to be the children's "mother").
The fairy-tale top wants to eat him and become one with him (at first he dresses up as Little Red Riding Hood, but later turns out to be the Big Bad Wolf).
The doctor top is a perverted, unscrupulous physician who wants to cut out his organs so he can admire them.
The monster top wants to refine him into a weapon and rule the whole world.
At first, the tops hate the bottom. Later, they realize just how irresistible he is and keep him tied to their side every day, not letting anyone else covet him.
There's only one top in the bottom's heart.
But then he discovers... these tops are actually different personalities split off from the main top!
Theme: Cherish the person by your side.