Responses
The concept is similar but this novel is more realistic.
Both MC transmigrated or started as high scholers. While one MC accept the new world as 'fun'. The other MC thinks that he is a imposter with low confidence.
Both has their charms and the endings are completely different from each others.
Yupppp
OK OK, so it seems here are the main points after binging this at just after midnight:
-MC got Isekai'd into the novel "bitterbloom" (was that the title??)
-MC's brother is technically his sister who also got isekai'd, but he doesn't know its her and feels resentment to this 'brother' because his sister didn't get the sane privilege. But this sibling clearly has recollection of some sort.
-ML is different to the ML of the novel, and is the sunbae of MC of OG world, but he also doesn't have recollection, hence unable to understand his unreasonable level of adoration towards MC.
-During significant plot change or recollection moments, these trigger MCs bleeding
-MC has his own harem collection cos he's so 'normal' unlike the actual characters of the novel, lmaooooooo
This is basically similar to Cosy Obsession since both MC and ML have isekai'd