Are there any romances between a guy and a girl on the rebound?

[Oobaka-san]

Like the name suggests, I'm looking for stuff where the main character ends up with a girl who pretty much just gets with him because she was just dumped, cheated on, or otherwise lost her love and wants some "comfort". Preferably something where the guy already loved the girl, but at least something where the guy does develop strong feelings for her well before she starts to truly get serious and get over her past relationship. I just feel like there's a lot of potential for interesting conflict and drama. Sure, in the worst case it could end up with a sort of "simp" hero who's just always there for a girl and doesn't care that she basically sees him as a backup (I in fact saw a series like that once long ago, I think by Solaris SVU though I haven't been able to find it, where the guy's love basically just shows up to bang him whenever she has a falling out with her boyfriend before going back to her boyfriend or maybe falling for someone else, and he seems to just accept this in hopes that someday she'll recognize him as more than just the guy she sees when there's no one else). However, there's plenty of room for more drama as the guy pursues a girl with lots of hang-ups and baggage, and maybe eventually has to confront her about whether she really sees him as the man she loves or just a fall back when/if things don't work out with her "real" boyfriend.

 

[Ferreas]

I have some stuff close to what you described but not exactly I think

Try this and let me know what you think:

My Love Story with Yamada-kun at Lv999 - Chill and cozy. Romcom about a couple who met in a video game after the girl got dumped.

Nanjou-san Wants to Be Held by Me - Can't guarantee you'd like it, a mess in many different ways, but just try a couple of chapters and decide for yourself.

This Kind of Thing is Fine - Chill and fun romcom about a friends with benefits, but it's an actual H-18, tho it's worth reading for the chemistry between main leads

 

[Lagiator]

REC - Her apartment got burn down, and the guy offer comfort
Jimoto - She got raped and broken ever since, and then her childhood friend back to the hometown
Blush DC - She got beaten up/violated by her pimp, then snapped and throw herself at anyone
Sankarea - She ded and the guy keep her as zombie

 

[Oobaka-san]

There seems to be a bit of confusion. When I say "on the rebound" I do not mean a girl who decided she didn't like her boyfriend and dumped him, nor do I mean a girl who suffered a major nonromantic trauma. I'm talking about a girl who suffered heartbreak; either she was dumped by the boy she loved, or she's having a fight with him. Might include cases where the boy just died. Whatever the case, we're talking about a girl who just lost or split from the boy she loved and probably still has lingering feelings for. Typically this would result either in a story where the girl is basically using the boy for "comfort" to try and fill in the holes, so to speak, or when she does fall for the main guy there's still a lot of baggage and pain, maybe even lingering feelings.

I remembered a one-shot from a series of shorts called Girl Friend, specifically chapter 17. The MC is head-over-heels for his girlfriend, who he's been dating for a little while. However, she is really weird when he wants to get intimate. She'll always tie him up and cuff him, then take off her top (but not her bra) and show off to him while he compliments her, but she won't let him get near her or do anything; the most she does is give him a foot job. He's complaining about this one day when someone suggests that she might have someone else she loves, at which point he notices she's staring at this extremely popular boy in their class. He finds out she used to date him and then asks her if she still loves him. She's horrified he knows about it but can't deny she still has feelings, but insists she loves him far more than that guy; the reason she won't let him touch her like that isn't because she prefers the popular guy, it's because she's afraid it'll end up like it did with him. That guy's only interested in virgins, so once she gave him her first he immediately dumped her, leaving her with a fear that if she has sex with her boyfriend he'll decide to leave because he got what he came for.

Another very unpleasant variant that has little chance of success (though I'd love to see one where the guy actually does win the girl's heart) is one where the girl is trying to make her boyfriend/ex-boyfriend jealous by dating someone else or otherwise uses the boy as a tool in an argument. Saw this once or twice in Hentai, very painful and unpleasant, especially since it easily works its way into NTR and/or revenge territories.

And don't worry if it's "H-18". I don't care whether a work is "Safe", "Suggestive", "Erotica" or "Mature". I've seen good stories in all of these.