Mc starts off as a true piece of trash, really, he is extremely insecure, he is obsessing over his inferiority to the perfect Mika, so when he dies he goes back in time and meets the teenage Mika, and after that he dies many more times, and every time he dies he either goes back to the original past, or to the possible future. Every little thing he changes in the original past creates multiple new futures, and along the way he finds out about Mika being raped, she had a stalker, her best friend commited suicide coz she was a target of bullying, and many more things happen, so slowly his 'wish to have her first time' turns into wanting to protect the young Mika from experiencing trauma, he wants to protect his friends, he wants to prove that his love for her is deeper than just his initial obsession with her virginity. That's where his character grows the most, coz he comes to realize in the latest chapters that he might not be her destined love, and that she could potentially be happy with someone else instead of him.