Two male protagonists, unlimited streaming
Not sure who is attacking or receiving. Because I seem to be a little offended by what I wrote.
I created a world view myself, which feels similar to ABO (but it's my own idea)
exmblt: Submissive to scriu. The specific degree of submission is determined by the level of scriu. It has pheromones and can be attacked or received.
Scriu: It is oppressive to exmblt. The specific degree of oppression depends on its own level. It has pheromones and can be attacked or tolerated.
Hecac: There is no pheromone, it is oppressive to Scriu, but it cannot completely surrender (except for Hecac level higher than A level), attacking
retic: has pheromones, which can forcibly mark hecac and scriu, but cannot completely surrender them (except retic level is higher than S level), and can be attacked or received.
Intention: It would be strange to be able to come out alive...