A [[Touken Ranbu]] character. The personification of the [[tantou]] "Shinano Toushirou" and one of the many tantous of the Awataguchi school swords.

He was named after its owner Nagai Naomasa, whose title was Shinano no Kami, one of Tokugawa Ieyasu's retainers. Before that, it was owned by Toyotomi Hideyoshi.

He has short [[red hair]] and [[green eyes]]. He wears [[black gloves]] and a [[military uniform]] with [[necktie]], [[shorts]] and [[thigh holster|thigh holsters]].

A haughty and spoiled child, Shinano prides himself of being a "treasured sword" and thinks himself to be superior to the rest of the Toushirou brothers. He often demands for the [[saniwa_(touken_ranbu)|Saniwa]]'s attention, asking for attention and/or physical contact. His catchphrase is "懐入っていい？ ([[futokoro haitte ii?|Can I stay close to you?]])". Because it literally has the meaning of "Can I be in your bosom?", it is sometimes jokingly referred to as a sexually suggestive phrase.

After his Kiwame remodel, [spoiler]he isn't recognized by his former masters, but gets to reunite with the Sakai clan again. It helps Shinano realize, however, that he took the kindness of his current family and Saniwa for granted. When he returns, he's still as spoiled and clingy as before, but he stops acting like an entitled kid.[/spoiler]

Voiced by [[Kobayashi Yuusuke]]. Artist is [[Kunimitsu (9nimi2)|]].
信濃藤四郎