(school slang) (being a part of) the "going-home club" (i.e. not participating in any after-school clubs)

a crank (a bent piece of an axle or shaft, or an arm attached to the end of a shaft or wheel, used to impart a rotation)

cubism

see amanojaku above

disappointment; failure to meet expectations; let-down

(computing) kibibyte

(usually prefixed with ご) in a good mood

Kigo, a word associated with a particular season in traditional Japanese poetry.

(Japanese folklore) Shapeshifting monster, 妖怪 (yōkai), which for a ruse takes the form of either a helpless baby or tiny old man, crying near woodland trails and crushes passersby who stop to help as it transforms to devour them.

(set theory) intersection