Translation guide
A playful fight using pillows, common at sleepovers. In Japanese, the most natural way to express this is with the phrase 枕投げ (makura nage), literally 'pillow throwing'. Other expressions exist but are less common.
A fun, informal fight with pillows, typically among children or at sleepovers.
The standard and most natural way to say 'pillow fight' in Japanese. Literally 'pillow throwing', it captures the playful action of throwing pillows at each other.
昨夜は友達と枕投げをして盛り上がった。
Last night we had a blast having a pillow fight with friends.
子供たちが枕投げを始めた。
The kids started a pillow fight.
A more dramatic or playful term, literally 'pillow battle'. It can sound a bit old-fashioned or theatrical, but is understood and sometimes used for fun.
修学旅行の夜は枕合戦で大騒ぎだった。
The night of the school trip was a huge ruckus with a pillow fight.
A more literal description meaning 'hitting each other with pillows'. It is grammatically correct but rarely used in natural conversation; it sounds explanatory rather than idiomatic.
子供部屋から枕の打ち合いをする音が聞こえる。
I can hear the sound of a pillow fight from the kids' room.