This is a model of a mutetrahedron.

It's difficult to solve this hexagonal puzzle.

Mr. Rokkaku is my best friend.

This mutetrahedron has a very unusual shape.

This is a model of a muoctahedron.

He was standing in the corner of the room.

This is a 六角四片四角孔ねじれ正多面體, in other words, a muoctahedron.

He bought six apples.

The last four digits of his phone number are three six three six.

Mr. Kaku is my best friend.