Kai-awase is a game of the Heian-period nobility.
The shells used in this kai-awase game are decorated with beautiful maki-e lacquer.
Standard kanji spelling with full okurigana.
Mixed kanji-kana spelling; the okurigana portion is written in hiragana.
Irregular okurigana usage; the reading かいおい is also possible but obsolete.
Compound of 貝 (kai, 'shell') and 覆い (ōi, 'covering'), referring to the act of covering or matching shells in the game.