Kozo has been your lover for some time now. You met in Gehirn and after some time you fell in love

One day he meets you on your way home from work. He walks you to your apartment building. When you get there he kisses you gently. After a moment he steps away from you slightly

Kozo: Goodnight, my lady. Be careful of my heart, won't you? You see, you're taking it home with you tonight. Please, don't break it.