happy lifelong partnership; living faithfully together till death
Only with reading かいろうどうけつ
A yojijukugo expressing the ideal of a married couple growing old together and sharing the same grave. Literary and somewhat formal.
The two vowed to live together faithfully until death.
Venus's flower basket (Euplectella aspergillum)
A deep-sea sponge. The name comes from the fact that a pair of small shrimp often live inside the sponge's glassy skeleton, symbolizing the idiom.
The Venus's flower basket is a type of sponge that lives in the deep sea.