Shinphin

Shinphin is the non-binary ship between Shin Tsukimi and a dolphin.

Canon
Shin has not interacted with a dolphin in the games.

Fanon
Along with other ships that a handful of YTtD fans pair Shin with random objects, this shipping is rare and can be considered a crack-ship. Fan art of Shin interacting with a dolphin exist, although they are photoshopped or in other ways made by awesome people. The ship stemmed from noticing how in some of his sprites, shin looks very similar to a dolphin.

One even made a headcanon of Shin meeting a dolphin after being kicked out of the band “Weezer” in the 1980s, later replaced by the singer-songwriter Rivers Cuomo.

The ship was created not seriously, by a few people in a discord server. After viewing some of Shin's sprites, they saw a resemblance between his sprites and a dolphin. They then jokingly made the ship, "Shinphin". They created fanart and photoshopped some images of shin and a dolphin all in good fun.

Headcanoned lore
The headcanoned lore of Shinphin is shown below:

"Days after Shin was kicked out of the Weezers, he sat on the curb of a road near the ocean, tears streaming down his face. His career was over. What would he do now? From the ocean, Shin heard a call, a whining noise. He looked over the rail of the ocean, and saw a dolphin. He instantly fell in love. He ran down a flight of stairs that led to the ocean, and took the dolphin in his arms. The dolphin whined in return, and rubbed against Shin's shoulder. Shin and the dolphin made a deal to meet each other everyday.

Shin then found a job at a local convenience store, and was making steady money. He would visit the dolphin daily, bringing little treats from the store for it. One day, Shin went to feed the dolphin, but instead was kidnapped and thrown into the death game. He wanders around the death game, constantly wondering when he'll meet the dolphin again. When he picks up a sacrifice card, he tries to find a way to get rid of it, he must see the dolphin again!

In the main game, Shin can only think about how much he wants to survive, and go home to see his dolphin lover. After he survives the main game, he wanders, wondering if there truly is any way to see his dolphin lover once more."

Fandom
It’s a crack ship without much recognition, but there is fanart and content of shin interacting with a dolphin.

Shinphin should not be taken seriously, it is only a joke in the fandom.