Oh, so that's why he transforms into a bird at the end. Thanks for the reference explanation!
In general, this Sensei is a shapeshifter of many feats. He sometimes turns into a woman, too.
Sensei...
I'm so sorryyy!What if something happened to you...A-... Arisu, you absolutely have to keep this a secret from Yuuka, alright!Worse than an injury...?Uwaaaahn...Uwaaah~
We're so high!Yuuka's always coming down on me about how I can't let you ride on me to go flying after all!It's fine, even if she says no!
But I won't forgive you for today for the rest of my life!After all, you were the one that told me not to listen to everything people tell me!Urk...