Without its usual crowd of spectators, Kaikyokan’s sunfish essentially started to fall into a deep-sea depression.

An aquarium in Japan has come up with a unique and out-of-the-box idea to cheer up its lonely resident sunfish after the facility closed for renovations.

A sunfish at a municipal aquarium undergoing renovation in this west Japan city became unwell, but recovered after its tank

The Kaikyokan Aquarium in Shimonoseki, Japan, which is undergoing renovations, revealed in a post on X that its staff had to think out of the box to help one of its sunfish struggling with the change.

Within a few weeks of closing for renovation, their 30-plus kilogram ocean sunfish began exhibiting strange behavior.

A solitary sunfish at an aquarium in Japan lost its appetite, began banging into the side of the fishtank and appeared unwell days after the facility closed last month for renovations.

TOKYO — A solitary sunfish at an aquarium in southwestern Japan lost its appetite, began banging into the side of the fishtank and appeared unwell days after the facility closed last month for renovations. As a last-ditch measure to save the popular fish, its keepers hung their uniforms and set up human cutouts outside the tank.

Renovation work at the Kaikyokan Aquarium in Shimonoseki, Japan, left one resident depressed in December. A sunfish suddenly stopped eating and exhibited strange behavior. This was apparently triggered by the lack of visitors.

"When an aquarium in Japan closed to the public for restorations, the aquarium's beloved sunfish grew lonely without visitors and lost its appetite — until aquarium staff pasted cutouts with photos of human faces onto the tank," the video caption explains. That's right — they made people! Have you ever seen something so sweet?

SHIMONOSEKI: A lonely ocean sunfish in a Japanese aquarium, which seemed to be missing its human visitors and caretakers during the facility’s closure, has found a surprising source of comfort.

The Japanese aquarium posted a photo on its official X (formerly Twitter) account on 3 January, showing the sunfish named Mambo swimming in its tank, surrounded by cutouts of smiling faces and staff uniforms on hangers stuck to the glass. The heartwarming but hilarious post has gone viral, receiving more than 12.5 million views and comments.

Japanese aquarium staff used cut-out human companions to cheer up a lonely sunfish, leading to improved health.