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 Super Mario anime series. Based on Japanese fairy tale Issun-bōshi (a fairy tale similar to Tom Thumb), it was released only in Japan.

Plot
In this fairy tale, there was a house in the scene; when suddenly a shooting star appeared in the sky and it flew down. When it flew down, Mario was born in that particular house as it glowed for a moment. Mario was a baby but was very small, as he was smaller than a hand.

When Mario was old enough; he wanted to travel independently during his life. He convinced Mr. Mario and Mrs. Mario that he was old enough to travel independently despite of his tiny self. When they are convinced; Mr. Mario gave Mario a weapon that is the same size as Mario for protection. The weapon is actually some type of pin. Mr. Mario then built a raft made from a pot, some switches and an engine, also a paddle for Mario to use. When Mario was ready; Mr. Mario brings the raft containing Mario onto the river where Mario would start traveling independently.

During the traveling on the water, Mario encounters a Spiny Cheep-Cheep that jumped out from the water, a group of Parabeetles flying forward, and a Blooper Nanny in the sky. Mario was widely amazed of seeing them. At that time, Mario was relaxing while the raft forward when suddenly, something happens at the bottom of the raft. The bottom of the raft reveals a Dry Bones that pops out calmly from the water. Mario uses the engines to move the raft; the rocket engines blast moving forward and popping out from one of the Dry Bones' eyes. After that, the Dry Bones returns to the water.

Mario then finds rain that has recently fallen from the sky. But it wasn't rain, it was the Lakitu with his cloud causing the rain. Additionally, the Lakitu's cloud also can throw thunderstorms making Mario hard to travel. Mario raft could not survive the water's waves. The raft tilted; then a big wave knocked Mario and his raft. He suddenly fainted.

When Mario opened his eyes, he sees Princess Peach looking at Mario directly. Mario then looked around; he was confused about what happened. Peach mentioned that when she was walking around town, she suddenly sees Mario fainted from the waves; so she picked him up with her hands and took him home. Both Mario and Princess Peach introduced each other, as they became friends.

Peach and Mario came outside into town, all of its surroundings were wonderful until they hear stomps. Mario and Princess Peach were surprised that it is Bowser. Bowser harassed Princess Peach; making both Mario and Princess Peach angry. Mario decided to take action to defeat Bowser. When Bowser hears that Mario will defeat Bowser; he laughs that Mario was too small to fight Bowser. Mario was being serious; but Bowser continued to laugh at his little size despite of having his weapon out. Bowser then attacks by simply stomping on Mario; but Mario quickly dodges. Princess Peach is concerned about the battle as Mario was so little while Bowser is huge. Finally, Bowser picked up the little Mario with his claws. Mario repeatedly squirmed around, trying to get himself free. Bowser ate Mario and was sent to his stomach.

Bowser is continuing to harass Princess Peach, but Bowser suddenly gets a feeling from his stomach. Mario was repeatedly poking his stomach with his weapon in different spots; causing Bowser to suffer the pain from his stomach. Princess Peach realized Mario is fighting inside his stomach. Mario continued to poke his stomach until Bowser was collapsed down to the floor. Bowser coughs out Mario from his stomach; he appears on his face.

Princess Peach was relieved that Mario is still alive, but Princess Peach suddenly noticed Bowser regains conscious. Mario quickly put into action as he cut off his horns. Bowser realized that Mario cut off his horns as Mario and Princess Peach laughed. Bowser runs away, humiliated. Princess Peach thanked Mario for defeating Bowser; when suddenly they saw a Magic Mallet that was dropped by the fleeing beast. Princess Peach picked it up and used this item to grow into its normal size. Mario and Peach were glad that Mario was at his normal size. Then get in Peach's hovercraft to explore around the city.