I'm not sure if I said this before but: THERE IS NO STRATEGY GUIDE FOR THIS GAME. At least, not one that's buyable. So I am taking it upon myself to create tips, tricks and tell people of glitches to make the game easier for them.
In this game, you can marry people, but ONLY AFTER you beat the main story.
After you beat the main story, you can decide to play as the girl or keep playing as the guy.
Sonja (Main character)
Makoto (you'll learn how after the main story)
Aiden (Main character)
IMPORTANT: The marryable people I just named off are key characters in this game and NOT JUST because you can marry them. It is EXTREMELY important you increase your friendship level with everyone in these lists (EXCEPT Aiden and Sonja) to level 6. Why?
Because, by getting your friendship level with the aforementioned people up to level 6, they will count as extra lives against the final boss of the game.