Kaiser de Emperana Beelzebub IV

Kaiser de Emperana Beelzebub IV (nicknamed Beel, Beelze or Beelzebub IV for short) is the namesake of Beelzebub.

Episode 4
He goes sleep-Skinny Dipping in his own urine.

Episode 57
In part 2, Hilda wins a raffle to go to a mixed bath for 5 people (plus a night's hotel stay), so the family goes (Beel also comes since children are free) and the 3 main chars go in the pool. The father comes too late.