...I don't know why it took me this long to realize it, but Tatsuta's head gear resembles a Halo while Tenryuu's resembles horns.
It's more like a pair of animals ears than horns. There was a joke in the official 4koma where Tatsuta asked if Tenryuu's head gears are meant to resemble wolf ears.
...I don't know why it took me this long to realize it, but Tatsuta's head gear resembles a Halo while Tenryuu's resembles horns.
On top of that their personalities are opposite, Tatsuta looks like an angel but is quite the troll/sadist, while Tenryuu had devil horns but is a total softie