The Ins And Outs Of aeiou

Today, I went on a sort of (date/Japanese lesson/ice-cream fest/walk around Tokyo) with one of the Japanese staff in my branch. It was fun, but the language barrier is a weird and complicated machine:

Phil: You ate Natto for breakfast? Gross.
Kiho: Well it was at 11. So between lunch and breakfast.
Phil: Oh, brunch.
Kiho: Like where we work?
Phil: No, that's a branch. Same word as the stick on a tree.
(Phil points to a tree branch, and then to the stump)
Phil: And this is a stump.
Kiho: Like you put on an envelope?
Phil: No, that's a stamp. A stump. A branch. And Brunch.
(Phil slams his foot down).
Phil: And that's a stomp.
Kiho: Wait, start again.

I am a good teacher, honest.