Play word 集団主義 集団主義 しゅうだんしゅぎ collectivism (giving priority to a group rather than any individual member)
Play word 集団就職 集団就職 しゅうだんしゅうしょく employment en masse (esp. of middle and high school graduates from the rural districts during Japan's post-war economic boom)
Play word 集団犯 集団犯 しゅうだんはん crime whose goal requires a large number of people acting together (e.g. insurrection)
Play word 集中日 集中日 しゅうちゅうび day on which many companies hold shareholders meetings (to limit disruption by would-be blackmailers)