Super Mario Issun-bōshi

Super Mario Issun-bōshi (or "スーパー マリオの Issun bōshi" in Japan) is the second OVA in the Amada Anime Series: Super Mario Bros., released only in Japan. It is based on the Japanese fairy tale Issun-bōshi, "The One-Inch Boy".

Plot
In this fairy tale, a shooting star gives a couple the child they had wished for, Mario, but he is only an inch tall. As the child grows older, he becomes adventurous and eventually sets his sights on a distant city, convincing his Mama and Papa to let him journey there on his own. Papa fashions Mario a tiny sword out of a sewing needle and builds his son a raft made from a pot, some switches and an engine, with a paddle for Mario to steer it with. He then brings the raft to the water and bids Mario farewell as he sets sail along the river.

Mario enjoys travelling. He sees a Spiny Cheep-Cheep jumping out if the water, a flock of Para-Beetles and even a Blooper Nanny flying through the air with its brood. At one point, a Dry Bones rises up under Mario, but he uses the rockets to fly his raft off its back and get back onto the water, taking a detour through its eye socket along the way, before it clatters apart and sinks back under the river. Later, Mario is caught in a storm caused by a Lakitu, who laughs as her cloud sends rain and lightning down upon the tiny boy, who struggles against the choppy water until a particularly large wave finally sinks his raft.

When Mario opens his eyes, he finds himself in a tiny bed on a bench in the city, with Princess Peach watching over him. She explains that she had been taking a walk when she spotted him washed up on shore, unconscious, whereupon she picked him up and took him back with her. The two become fast friends and Peach walks Mario around the city on her shoulder, but the happy moment is broken when they hear heavy footsteps approaching. Peach screams in fear and tries to flee, but she and Mario soon find themselves face-to-face with the monstrous Bowser, who immediately starts harassing the princess.

When Mario brandishes his sword and tries to force Bowser to stop, the Koopa merely laughs and tries to stomp on the tiny boy, before picking him up and swallowing him whole instead. Peach is horrified, but Bowser simply returns to harassing her, only to double over in pain as Mario begins to poke and slash at the inside of his stomach with his sword. Bowser soon collapses and coughs up Mario, to Peach's relief. Bowser regains consciousness with the tiny boy still perched on his face, but Mario quickly cuts off his horns and eyebrows with three strokes of his sword, causing the Koopa to run away in humiliation. Peach thanks Mario for defeating Bowser, and then notices a magic hammer he had dropped as he fled. When she picks it up, its magic causes Mario to grow to a regular height. The two then get into Peach's hovercraft to explore the city some more.