Welcome to Demon-School, Iruma-kun

Iruma and Lead end up being trained by Robin's relative, Barbatos Bachiko. Bachiko is very skilled and was personally asked by Sullivan to assist Robin with tutoring the kids. They were supposed to have a rather hard training schedule... but all Bachiko asks them to do is random errands. Lead has had enough of that and goes back to Robin. Iruma is left frustrated and alone. He learns that Asmodeus and Clara have been training and decides to take matters into his own hands!