SMG4: Mario's Inside Story is the eleventh episode of Season 10 and the five hundred and sixty-fourth overall to be uploaded by SMG4.
This episode was aired on March 28, 2020.
Mario ate some bad spaghetti...
The episode begins with SMG4 creating a robot inspired by Carl Wheezer from Jimmy Neutron. As he was complimenting his "masterpiece", Luigi burst into the room with a sick Mario in tow, destroying Carl Wheezer. As Mario stated, he was about to take a poop in the basement bathroom when he found spoiled spaghetti, which according to Luigi, was probably there for the past 10 years. Due to his gluttony and stupidity, Mario unsurprisingly did not listen to Luigi and ate it, which resulted in food poisoning. SMG4, annoyed at Mario's gluttony, grabbed Saiko from the foyer and told her and Luigi to go inside Mario's body and fix the disease. Using E. Gadd's shrink ray, he shrunk Luigi and Saiko (causing her to believe SMG4 turned her ugly), put them inside a capsule, and had Mario swallow it.
The two ended up inside Mario's stomach, which was filled to the brim with spaghetti plates, Spy, Tinky Winky, Eggman Football and a can of bleach, causing Saiko to criticize Mario for his eating habits. They discovered the virus that was causing Mario pain and taking the shape of Mario, evading their attempts to capture it. The virus then created a hammer and smashed the stomach, forcing Mario to digest everything inside. Saiko was forced to grab a piece of spaghetti, wrap it around Luigi as if it was a rope, and flung it towards the blood vessel the virus went through. However, the virus managed to deflect Luigi and with the inertia from the flinging, they ended up in a different blood vessel. There, Luigi and Saiko discovered several Mario Cells who help keep Mario's vital organs in state. They initially mistook Luigi and Saiko as a threat but calmed down after Luigi revealed he knew Mario (through a picture on his iPhone which showed him and his brother, who was streaking in a mall, being chased by Hal Monitor), and welcomed them in. Inside Mario's organs, Saiko was disturbed upon learning that the Mario Cells worshiped Mario as some sort of god, even more than seeing him hump food naked.
Understanding the situation upon being asked where did the virus go, the cells formed up a ladder for Luigi and Saiko to climb up, getting them inside the area where Mario's brain rested. The brain was revealed to be smoking and mostly small (hence Mario's stupidity). The virus once again appeared and proceeded to enlarge, overpowering Saiko. Luigi begged Mario's brain for help, promising 10 plates of spaghetti with mayonnaise, 1 truck of vanilla ice cream, and Old Man Walker. The brain happily took the offer and killed the virus easily with a baseball bat, minigun, and bazooka. This resulted in Mario cured. SMG4 was happy that Mario was cured, but when asked how would they escape, he revealed it was complicated. Mario then revealed he was going to take a poop in the bathroom, and both Saiko and Luigi, realizing they would get out of Mario's body by his anal, screamed loudly in panic.
- Carl Wheezer robot
- Bob Bobowski
- Fishy Boopkins
- Tinky Winky
- Hal Monitor
- Old Man Walker
- Carl Wheezer robot malfunctioned by Luigi after Luigi burst into the room.
- Tinky Winky got digested inside Mario's stomach. (Debatable)
- Spy got digested inside Mario's stomach. (Debatable)
- Mario Virus got killed by Mario's brain.
- SMG4: Mario University and SMG4: War Of The Fat Italians 2018: Luigi mentions SMG4 having a degree in Memeology.
- SMG4: Mario Runs Out Of Toilet Paper: The mass rolls of toilet paper Mario received at the end of that blooper is shown when Mario uses the bathroom.
- This is Luigi's first main role in a blooper since SMG4: The Weegee Uprising.
- With this episode, Luigi is promoted to the main character in Season 10, alongside SMG4 and Mario, though he remains a deuteragonist overall.
- While the succeeding video is SMG4: The E G G, a video entitled SMG4: Goodbye Meggy was posted on April 2, 2020, as an April Fool's Day prank to SMG4's Discord server to fool fans that Meggy was leaving SMG4. The video instead consisted of YouTuber The King Crane testing a Grand Theft Auto mod featuring Pickle Rick from Rick & Morty and the thumbnail of the video with edited audio of "Doin' Your Mom" by FAttY SPiNS. The video was quickly removed afterward, but a reupload can be found somewhere.
- This episode was uploaded on the same day SML Movie: Jeffy Goes Bowling! was uploaded.
- This is the first video since SMG4: The Tari Abnormality in which Tari appears but Meggy doesn't.
- This is so far the last episode were Toad can be seen together with SMG4's Gang.
- From this episode onward, captions are auto-generated due to the removal of community captions.
- Mario & Luigi: Bowser's Inside Story: This blooper is based on this video game.
- Osmosis Jones: This blooper is also based on this live-action/animated film.
- COVID-19 pandemic: The Mario Virus itself may be based on SARS-CoV-2.
- North Korea: The inside of Mario's blood and heart system is similar to the system of North Korea where the Mario Cells constantly worship Mario (similar to how North Koreans worship Kim Jong-un), the Mario Cells initially reject Luigi and Saiko (similar to how North Korea disallows outsiders), and there's even a giant golden statue of Mario that the Cells worship, similar to the giant statue of Kim Il-sung in North Korea.
- KonoSuba: Saiko's Super Saiko Fist is similar to Aqua's God Blow which both failed against a giant enemy. The Mario Virus for Saiko & a Giant Toad for Aqua.