Kimi no Sumire
A steps into a fight involving B (isn't much help but B appreciates the sentiment), B starts to hang out with A everyday. Very slow and natural getting together, pure, adorable. No real conflict.
Baby, Sugar, Succubus
This is incredibly, sickingly sweet. Like very sweet the MCs are very much in love with each other and respectful to each other, very soft vibes. A has a huge dick, runs into B who is a succubus. Perfect match so they hook up and establish a relationship.
Kono Ore Ga Omae Nanka Suki Na Wakenai
Person A tries to be friends with B but gets brushed off (due to a misunderstanding), B transfers into school with A, and forgets about A. A tries to get revenge on B however over the course of the plan forgets the objective and falls for B. They get together, slight obstacle with B finding about A's plan but gets resolved.
Nee Senpai, Oshiete Yo
Person A moves into school dorms, Person B is supposed to guide Person A in the dorms. Person B is closed off because of some stuff from middle school. Over time Person B warms up A, A catches feels and tries to hide them (terribly so, B can clearly tell). No real conflict, pretty cute.
Restart wa Onaka wo Sukasete
Sequel Deals with B's backstory more and focuses on the evolvement of B as a person and his relationship with A. Dealing with "marriage" (partner acknowledgement) Finding out about real family
Kimi to no Dogfight