Hattori greets Kenichi one morning with "O-ha!". This word, and the accompanying hand actions, were coined by Shingo Mama, Shingo Katori's female alter ego.
Kenichi gives Hattori a bowl of rice and mayonnaise. Katori is famous for his love of mayonnaise, with rice and mayonnaise being one of his favorite snacks.
There are a few cameos in this film, which include Katori's fellow member of Smap, Tsuyoshi Kusanagi, and Hiroki Kawada, Gori's partner from their comic duo Garage Sale.