Manga where guy breaks up with / rejects girl / uses girl in a bet / is in love with someone else and comes to regret it later

athenalalaine said:
the guy either breaks up with the protagonist, rejects her confession, uses her in a bet or is in love with someone else and comes to regret it later?

Zurajannai said:

all of that in one?
that's hard to find lol

The World Only God Knows could fit all of them except for point "uses her in a bet", well, that's pretty cruel to begin with

manga where "the guy either breaks up with the protagonist, rejects her confession":
Suzuka (reverse, it's the girl rejects his confession, anymore, will be spoiler)
Kimi no Iru Machi (about the same thing as Suzuka)
Ichigo 100%

mogu_ said:
Errr....Ao Haru Ride?

Devasabu said:
I think Fated To Love You Pretty Much fits everything other than "uses her in a bet" but it's a chinese manuha though
Also Bitter Virgin might fit because the guy initially says he'll date any one other than the girl to his friends and later regrets it but it's not exactly a "rejection" because the girl just overheard his conversation and didn't technically like him either....and I'm gonna shut up and not spoil it anymore,give it a try it's pretty good.

As for a girl being bet,try Gamble Fish but there's not really a regret part because the guy is too smart(read too frigging OP) for his opponents and wins,also it's a harem not a romance and I think he bets the girls more than once