Ojousama☆Yomeiri Kousou!

On his first day at a new school, Mamoru Amakawa receives two love letters — which sounds flattering until you find out one is from the daughter of the gang boss who controls the northern half of the city, and the other is from the daughter of the mafia leader who runs the south. These two women, Sakura Sumiyoi and Ageha Kurosaki, absolutely cannot stand each other, and now they're competing hard for the same guy's attention. Mamoru is stuck in the middle of a rivalry that has very real power behind it. This is a short two-episode OVA from 2012, adapted from a light novel, so it moves fast and keeps things focused on the central competition between Sakura and Ageha. The appeal is the contrast between the two heroines — their personalities are distinct, their aesthetics reflect opposite sides of this divided city, and watching them clash while simultaneously trying to charm the same person carries a genuinely comedic energy. The romantic tension and the gang-world backdrop give it a slightly elevated stakes feeling compared to a straightforward romance. If you enjoyed the chaotic relationship dynamics of My Bride is a Mermaid, where the romantic interest comes packaged with serious faction politics, this covers similar ground in a much more compact format. It is a hentai title, so go in knowing that — but if that fits what you are looking for, the rivalry setup gives it more personality than most entries in the genre.