Where does “草短” come from?

草短 (Japanese) comes from Japanese 短冊, from Japanese 短, from Middle Chinese 短 — short.

草短 (Japanese): A card combination made with every hanafuda card depicting a red tanzaku without writing on it, except for that of the suit; i.e. a combination of the wisteria tanzaku card, the iris tanzaku card, and the bush clover tanzaku card

Definitions

A card combination made with every hanafuda card depicting a red tanzaku without writing on it, except for that of the suit; i.e. a combination of the wisteria tanzaku card, the iris tanzaku card, and the bush clover tanzaku card

Ancestry of “草短”, step by step

草短 traces back through two separate lines of ancestry.

via Japanese 短冊

Step	Language	Word	Meaning
1	Japanese	短冊	tanzaku; A small strip of paper that can be written on, especially those hung on bamboo or other trees during Tanabata
2	Japanese	短	fault, weak point; minor
3	Middle Chinese	短	short

via Japanese 草

Step	Language	Word	Meaning
1	Japanese	草	grass; a weed; a herb
2	Middle Chinese	草	—

Every word from Middle Chinese 短 →Every word from Japanese 短 →Every word from Japanese 短冊 →