Most characters don't have hashtags, and Sharada is the only one who has her own. All the others are potential couples. Sharada only has one because I hardcore jumped on the Sharada hype train when she was conceptualized on the pad. So basically entirely my irrational Sharada fangirlism.

Also, NK, if it were me I'd wait until next season, as I'm doing with Mizuki. But I don't think there's any harm in bringing her in now and significantly increasing Athalia's average temperature.