The term "main plot" refers to the most important or central storyline in a book, movie, or story. It focuses on the main events and conflicts that drive the narrative and engages the audience the most. Full definition
At main plot points during the game you can make enormous game - changing decisions which can result in characters dying or, even worse, hating you. (gameluster.com)
There are five main plot lines for each girl with multiple endings. (fsat.ru)
The game has two others that are alternative takes on the games main plot, and none of them truly gives any sense of fulfillment. (thebuttonsmashers.com)