Mt. Itoi is a starting stage in Ultimate Company Smackdown. It originates from the EarthBound series, and is Ninten's home stage.
Mt. Itoi is one of the final areas in Mother, and it is where Ninten receives the final two of the Eight Melodies. Shigesato Itoi rushed the development of this area, avoiding difficulty testing and making Mt. Itoi extremely difficult.
Mt. Itoi features a large cave at the base, with a plateau at the end. Higher up is a lake.
Mt. Itoi is a purely vertical stage, without much horizontal room. It has a large amount of grabbable ledges, which can be climbed to eventually reach the top. Mt. Itoi has no blast zones on the sides, and it is nearly impossible to KO off the top due to the stage's vertical reach. These things combined with easy recovery at the bottom of the stage make it so that health reduction is the main way to KO.
At the beginning of the stage, there is an enterable cave, which is noticeably darker than outside. Inside, there is a large room with two high ledges, one on either side of the cave. On the left ledge is a door out. The combatants can't reach most of Mt. Itoi unless they pass through this cave.
Halfway up, there is a large lake.