A Pure type 2nd year, Ayumi is a tsundere character who loves baking.
...s- she didn't bake it for you, stupid!!

In M's songs, Ayumi will most likely take the role of Rin, and in Aqours, she will usually be You, though this is subject to singer preference on a song-by-song basis. This does not mean she needs to sound like either, only that she is likely to sing those lines.