Mutsu (陸奥 Mutsu) is the merchant fleet Kaientai's 2nd in Command, but is in fact the one running the company. This is because her 'natural idiot' leader Sakamoto Tatsuma is always disappearing. Once things got to the extent that she had to install a homing device in his pistol, so that when he fired it, the homing device would clue her in to his whereabouts. 
She has brown, straight hair and brown eyes. She usually wears a sedge hat & men's clothing.
Back in her younger days, Mutsu had short hair and wore a cheongsam like clothing with a mini skirt and long a coat.
Mutsu is the opposite of Sakamoto, acting as the leader of the Kaientai. She is usually calm, collected, and serious. In the Renho Arc, however, she gets angry when Sakamoto plays Uno instead of thinking of an actual plan to save Earth. Practising what Sakamoto preaches; when her own leader got captured by aliens, she ensured the safety of the ship's guests before proceeding to help him.
- Mutsu's historical precedent is Mutsu Munemitsu 陸奥宗光, a diplomat and one of the members of Sakamoto Ryoma's Kaientai.
- In chapter 477 of the manga (Always Open Bags Like They Have 50 Million in Them) it's revealed that Mutsu is actually an Amanto and her father was the President of a Space Pirate group, similar to the Harusame, that specialized in Human Trafficking. Though Sakamoto bought their ships and Mutsu along with it, which is how she came to work for him.
- She also states that she picked up the Tosa accent from Sakamoto.
- Gintama Anime. Episode 57.
- Translated from 空知英秋 Sorachi Hideaki, 銀魂五年生 Gintama 5th Graders (Gintama Official Character Book 2), 集英社 Shueisha Jump Comics, page 120.
- Translated from 空知英秋 Sorachi Hideaki, 銀ちゃねる! Gin Channel! (Gintama Official Character Book), 集英社 Shueisha Jump Comics, page 136.