>>536363120
In Fire Emblem, you control a dozen units in a battle. They are each individual characters with different weapons, likes and dislikes, powers and so on. When units fight side by side, they get support points. Enough support points, they have some dialogue and reach a support rank(meaning their stats are raised in proximity. Whichever unit has the highest support with another will have an ending together with them.
The player character is exemt from this, as you can pick who you want to end up with at the end.
Oh and in a few games you can have children together