Japanese by Example
Learning through examples in manga

Suddenly remembering with 思い出す

からかい上手の高木さん » Volume 1 » Page 114

Takagi and Nishikata share an umbrella to walk home after school. Takagi says she completely forgot the term for two people sharing an umbrella. Nishika, with embarrassment, mutters that it’s あいあいがさ. When Takagi asks him to repeat it louder, he keeps quiet in his embarrassment.

「あ! (おも)()した相合(あいあ)(がさ)だ。」
"Ah, I just remembered, it's 相合(あいあ)(がさ)."
"You totally didn't forget it!"

Nishikata’s embarassment stems from あい being the same pronunciation as (あい), a coincidence that lends to the idea of romance between two people who share an umbrella.