Looking for a manga

Iḿ looking for this manga where the girl is born with flexibility and she goes to a school in the countryside where a rich boy falls in love with her. I also remember a clocktower and and them getting stuck in some place and people try to get them out by using dynamite. I faintly remember when making a bet while the clocktower was being fixed and the boy says that while the clocktower is being fixed, time would stop for them or something like that? May I get the title to this manga?