A depressed author. A concerned editor. An eccentric mushroom researcher. And a strange pink mushroom... that turns into a dog?! Put this all together and you get Mushroom Pup. Mushroom Pup tells a heart-warming tale of the power of friendship, a dog's love, and the dangers of dwelling on regrets. With the help of his friends and the mysterious Mushroom Pup, Hotaru Yuyami, a grieving picture book author, slowly begins to move forward after the tragic loss of his beloved dog, Hanako. Full of laughs and warm moments, Mushroom Pup is sure to find a place in your heart.

In 2015 A.D., Dr. Yamanoue, the Secretary of the Science Ministry, who devotes himself assembles the Android robot on an artificial island. He intends to live together with him as his own son. But the robot has a deficiency in his electric brain. He comes to the conclusion that Dr. Kawashimo's help is essential to correct his defective rain. Although they are friends, they are rivals not only in private life but also in scientific study. Dr. Yamanoue is very jingoistic and only thinks of the robot as one of his strategic arms. On the contrary, Dr. Kawashimo is a pacifist and devotes his affection to robots. Dr. Kawashimo hurries to the island on request of Dr. Yamanoue, taking his pretty young daughter Miri with him. Arriving on the island, Dr. Kawashimo sets the electric brain into Jet Mars, a robot boy. Thus Mars comes into the world. Everything is new to Mars and he doesn't know what is good or bad. On the next day he lifts Dr. Kawashimo and Miri up onto the building. When he sees a glint of moisture in Miri's eyes, he has a mysterious feeling in his mind. Then he asks Dr. Yamanoue what it is. He is taught that it is a tear a weak girl sheds, but, a strong man never does. One day, the electric brain of Fainton, another robot, is put out of order. So Fainton goes-on a wild rampage and the island is plunged into a crisis. When the seawater runs into the facilities from the big hole made by Fainton, only Mars stands in amazement and is quite at a loss what to do just then Miri exhibits her ultra ability and covers the big hole. Led by her, Mars also carries a sheet of iron and makes repairs. At last they rescue Dr. Yamanoue and Dr. Kawashimo from being washed by seawater. Miri is the robot made by Dr. Kawashimo. Mars learns how to cry and learns how to perform a kind deed.

The story follows Tsunehiro Sasaki, a depressed college student burdened with debt and being told that he only has two years left to live. After falling into the sea while on the run from debt collectors, Tsunehiro is rescued by friends Hana and Takaaki and soon becomes hooked on fishing himself.

When sarcastic loner Haruka gets transported with his class to another world, he's not wild about adventuring, but he wouldn't mind having some cool powers. Unfortunately, he's last in line when the magic cheat skills get divvied up, so by the time it's Haruka's turn, there are no good choices left. Now Haruka will have to take on this fantasy world the hard way–on his own, with a hodgepodge of bizarre skills! When infighting and chaos break out among his classmates, can this loner come to the rescue?