I think it's painfully obvious at this point (he's wearing a goddamn haori under his labcoat), but just in case anyone missed it, the new teacher is a reference to famous member of the Shinsengumi Okita Souji.
i lowkey hate it when people translate sensei as teacher and STILL use it as an honoriffic... either use "okita-sensei" or just dont bother with the teacher part.... otherwise its just weird and awkward