Two player characters can engage in support conversations (which they are highly recommended to be played out in-game, however before/after a battle and not during) assuming they meet the prerequisites to do so. These support conversations may be about anything, however the final support (known as S-rank Support) almost always leads to the two units marrying, even if they are the same sex, however this can also lead to a complete devotion or other something of that nature. Supports can only be administered after a certain amount of times, as seen in the table below. (Note: Fights are cumulative from battle to battle.) Also listed are bonuses units get for supporting another unit. (These only apply if the unit is adjacent).
Each unit can only S support one unit. Only the highest support applies to a unit when calculating bonuses granted from adjacent allies.
Below is a Fast and Slow track for supports in case a game is large, or may be long running and requires more time to build up more supports.