So here's a quick ending guide:
First choice: "Run away in a panic" will give you the virgin ending where our boy doesn't get any and the game ends short. Choose this if you're having doubts about making a married mom commit adultery.
Choosing "Run for sex partner" will initiate the adultery.
Second choice: "Try swapping" will give you the netorare and gangbang ending where Misako will eventually end up attending gangbangs without telling you. Choose this if you want to see the happy housewife you know become a cock hungry nympho.
"Do not try swapping" will give you more options.
Third choice: "I'm curious about what I said earlier" will give you the incest ending, which is hilariously probably the only ending in the game where everything continues as normal afterwards. Choose this if you don't want to see heavy consequences for the characters.
"I don't care" will give you more options.
Fourth and final choice: "Because I want Misako to be my woman" will give you the pregnancy ending, and the most wholesome ending for both Misako and Kengo. Choose this if you want to see Kengo and Misako continue their relationship by having a baby together.
"Because I want to deepen her relationship with Misako" will give you the soapland ending. Misako works in a soapland and Kengo is her best customer. The two just remain sex friends with no romantic feelings. Choose this ending if you're afraid of committing to the hot milf 15 years older than you and would rather see her become a prostitute in a soapland for her needs.
This is kind of why I enjoy VNs. If you dislike a certain ending you can always choose better, whereas you can follow a serial hentai manga for a year or two and there's no gurantee the one single ending will satisfy or fulfill you. Sadly this game is way too short for character development for to matter but yeah.