傘 on Japanese Wikipedia

Compound of 相合 (aiai, “doing things together”) +‎ 傘 (kasa, “umbrella”). The kasa changes to gasa as an instance of rendaku (連濁).

相合傘 has a strong romantic implication, stemming in part from a play on words. The first two characters are pronounced あい (ai), the same as the word 愛(あい) (ai, “love”), and thus the connotation is that both people under the umbrella are in love.

• (Tokyo) あいあいがさ [àíáígáꜜsà] (Nakadaka – [5])^[1]
• IPA^(key): [a̠ia̠iɡa̠sa̠]

相(あい)合(あい)傘(がさ) • (aiaigasa) ^{←あひあひがさ (afiafigasa)?}

1. an umbrella or parasol shared by two people, which alludes to a romantic situation

   相(あい)合(あい)傘(がさ)で散(さん)歩(ぽ)している二(ふた)人(り)が向(むこ)うに見(み)えます。

   Aiaigasa de sanpo shiteiru futari ga mukō ni miemasu.

   You can see a couple walking together under an umbrella over there.

   • 1999 February 20 [1994 December 15], Rumiko Takahashi, “ＰＡＲＴ(パート).６(ろく)　伝(でん)説(せつ)の相(あい)合(あい)ガサ [Part 6: The Legendary Coupling Umbrella]”, in らんま½ [Ranma ½], 9th edition, volume 31 (fiction), Tokyo: Shogakukan, →ISBN, page 87:

     そのカサに一(いっ)緒(しょ)にはいった二人(ふたり)は必(かなら)ず相(そう)思(し)相(そう)愛(あい)の仲(なか)になるんですって、だから伝(でん)説(せつ)の相(あい)合(あい)ガサ。

     Sono kasa ni issho ni wa itta futari wa kanarazu sōshi sōai no naka ni naru n desu tte, da kara densetsu no aiaigasa.

     Legend has it as long as two people are under that umbrella together, they’re always in love, and that’s the legendary coupling umbrella.

     ロマンチックよねー。

     Romanchikku yo nē.

     How romantic.

2. (figurative) an infatuation between two people

   その二(ふた)人(り)はもう相(あい)合(あい)傘(がさ)だわ。

   Sono futari wa mō aiaigasa da wa.

   Those two are already sharing an umbrella, don't you know.

3. (slang, figurative) a love affair, a romantic relationship
4. a simplistic doodle of an umbrella, usually topped with a heart, with the names of two people who are said to be in love written on either side of its handle (compare the writing of names inside a heart)

   相(あい)合(あい)傘(がさ)の書(か)き方(かた)ってどれが正(ただ)しいの？

   Aiaigasa no kakikata tte dore ga tadashī no?

   What's the right way to draw an aiaigasa?

• 相(あい)傘(がさ) (aigasa)