Profile posts don't count towards your message count, and I think I farmed a thousand likes from a hyper long profile post a while back... I think Hydra was there so he might remember.
You accumulate likes proportionally to how active you are I suppose, as well as the type of people you hang around. Likes flow pretty freely here, and I presume the Fiction Roleplay is where Shen farms the rest of his likes.
Add in creative works and you've got a pretty solid source of likes.
How could you D: !?
I digress though, just splurge around charms and you'll rake in likes, that's how it works on NUF too. Speaking of that, did you ever make an account to join the Adventurer's Guild? I'm thinking of using some of the missions/bounties that are there for this Role play. Gives something for me to do with Sagisō as she goes solo, and I won't have to plan missions myself xD