The League of Villains and Giran seem to share a close connection with each other. Serving as the League's broker, Giran is responsible with providing weaponry and informs them on current news relating to Hero society. Despite his concerns about Tomura's leadership, Giran seems perfectly willing to help contact other members on his behalf. He is also responsible for recruiting Twice, Dabi and Himiko Toga. It is to be noted that Giran has kept up with Twice since his induction into the League. For this, Twice considers Giran a 'swell and wonderful' guy for giving him a place to belong to. 
Giran is very loyal to his customers. He refuses to talk even while being tortured for information by the Meta Liberation Army. The loyalty seems reciprocated, particularly by Twice and Tomura, as they both insist that he be released when hearing of his capture. Although, Dabi expresses a lack of concern for Giran's capture while Mr. Compress and Spinner are deeply worried about the Army's numbers and plans the League still sets out to rescue Giran.
Like other companies that barge into his industry Giran despises the Detnerat Company and additionally it's president and CEO, Rikiya Yotsubashi. While captured by the Meta Liberation Army, Giran refuses to given any information on his clients especially the League of Villains. He mocks Rikiya's face, refuses his bribery and insists that he does things the right way. Giran admits that he won't do business with people he does not like. In response, Rikiya has Giran's fingers chopped off and spread about in area where the League had been.
While speaking to Tomura, Rikiya praises to Giran for his resolve to not give any information on the League or to show any anguish while having his fingers removed.
Giran appears to have a purely business relationship with Knuckleduster, although he considers him a valued customer. Giran has provided him a variety of equipment over the years for his vigilante activities to deal with difficult Quirks.
- ↑ My Hero Academia Manga and Anime: Chapter 68 and Episode 38.
- ↑ 2.0 2.1 2.2 My Hero Academia Manga: Chapter 223.
- ↑ 3.0 3.1 My Hero Academia Manga: Chapter 224.
- ↑ 4.0 4.1 My Hero Academia Manga: Chapter 219.
- ↑ My Hero Academia Manga: Chapter 57.
- ↑ My Hero Academia Vigilantes Manga: Chapter 26.