Derogatory slang for pachinko, referencing the stereotype that many pachinko parlors are owned or run by people of Korean ancestry. Offensive and not used in polite conversation.
That place is full of pachinko machines (derogatory).
Standard, neutral term for pachinko. 朝鮮玉入れ is a derogatory slang variant.
Compound of 朝鮮 (Chōsen, 'Korea') + 玉入れ (tamaire, 'ball-inserting'), literally 'Korean ball-inserting', a derogatory reference to pachinko.