A lot of her stories are like this. A lot of sleeping around, friends with benefits, groups of buddies, many of whom have slept with each other at one time or another, sex for money, etc. It's like sex is just something they do, and relationships are separate. Seldom are they really happy. I also don't like it when a character has sex with someone, and then immediately after has sex with someone else, like in the 2nd story. Not because it was cheating, but because I wouldn't want to have sex with someone I liked knowing that they just did it with someone else, so it bothers me a little. Anyway, some of her stories are on the more cheerful, lovey side, but most of them leave me feeling a little melancholy.
yup! that's exactly how it is for me too, i don't like it when i know that the person i like had sex with someone else especially when we are in a committed relationship. tbh it disgusts me to think that I'll have sex with this person who had just sex with another. though at this manga they are not official but most of the manga with this same trope are. and it's normal for us to be possessive of our relationship and partner that's why how can we condem people who judges and hate people who had an affair or plays around. we are of a naturally possessive beings.
this is what you call pointless cheating. i get that it wasn't exactly cheating, and that tetsu was raped by mdfkn midori. but what i mean by pointless is that the manga acts like the rape never happened, and they were all buddies again just because midori felt sorry. i'm not into rape/cheating element but it could've been better used in the story. (〜 ̄△ ̄)〜