So the only reason he chose ass-chan is because they fucked, and he only agreed to go on a date with her because he thought he can have more of dat ass. So he's just horny, no romance.
Now we know other girls still have a chance.
This is going beyond jus simple ecchi.
I've read somewhere that the skin on human lips are the same skin that are on vaginas so technically, that was a kiss.
She just used some scientific information and invented some shit to make it look like she helped save the world at all. In the end, the main point of the thesis is that the worms are the ones turning people into monster which has been obvious from the start. Even saying that the work of the...
The way he grabs her hair is kinda lewd (no, I don't have such fetish) and the face she makes is hella cute. Add how she looked while saying "more". Love this chapter