Red can gain or lose relationship points with male and female characters, with opportunities to eventually become a romantic partner with the latter. Relationship points are one of the main factors in progressing on any character's routes or side stories.
Gaining Relationship Points
Having direct conversations with a character is the most common way of gaining relationship points. Depending on Red's response, choices may result in gaining, losing, or achieving no relationship points at all with a character.
In addition to scripted conversations, once free exploration is unlocked, Red can voluntarily spend time with any character he knows to increase relationship points. These hangout sessions are meant to supply additional points that Red may need in order to progress on a character's route.
In some occasions, a choice that Red makes can indirectly lead to gaining or losing relationship points with a character that's in a different location at that time.