Chiaki and Tsumugi have never talked to each other in canon, but they've had a short conversation within Ultimate Talent Development Plan.
When playing as Tsumugi, during the fall school festival, Tsumugi decides to exhibit all the cosplay she's made so far. If chosen, Tsumugi will welcome Chiaki to her cosplay exhibit. Chiaki states that she saw some video game character's outfits and came to look. Tsumugi then asks her if she ever wishes to become a video game character, to which Chiaki denies. Chiaki then goes on to compliment Tsumugi's cosplay, stating that "it feels like the character's have popped right out of the screen," to which Tsumugi blushes and thanks her.
The two have some interactions in Danganronpa S: Ultimate Summer Camp. In one, Tsumugi reacts with surprise upon learning that Chiaki has never entered any world championships in esports. Tsumugi encourages her to try competing in one. At the campfire, Chiaki takes inspiration from Tsumugi's story about cosplay. This was for her to come up with a scary story about forgetting to save her progress in a video game.
Though very different in similarities, they are also pretty similar. Tsumugi is The Ultimate Cosplayer. She has mentioned she mostly cosplays famous anime characters and possibly famous video game characters as well. Chiaki is The Ultimate Gamer which could also be a talent involving the fandom. In Tsumugi's splash art, she is shown with a Hatsune Miku wig. Miku is very similar to a video game character. Chiaki might have heard of her.
- Chiaki Nanami – “Your outfits are so well-made. I can instantly tell which game character's clothes these are. It's as if the character jumped right out of the screen... I can see why you'd be into this.”
- Tsumugi Shirogane – “R-Really? Thank you... If you start to get interested in cosplay, talk to me any time. I'll fully support you!”
- — The Two During Their UTDP Event
The ship became popular due to the similarity of the girls' talents and how well they could mesh in a relationship. With Tsumugi as the Ultimate Cosplayer, and Chiaki as the Ultimate Gamer, it's easy for cute activities to take place like Tsumugi making cosplays of Chiaki's favourite video game characters for her. Their dynamic of Fandom Geek x Fandom Geek is also what drives this ship. Despite all of this, Shironami is still considered a rarepair. The both have more popular ships, such as Shironaga, Shiromami, Kaemugi, Saimugi for Tsumugi. Hinanami (AI), Komanami, Komahinanami, Soniaki, Nanamiki, and Kamunami for Chiaki respectively.
In most fan-works, their relationship is mostly described to be energetic due to Tsumugi. In fanart, the both of them are usually hugging. Tsumugi is commonly depicted as the "controller" or mother of the relationship. However, some are more unique. In one specific fanart from Instagram (as seen below) Tsumugi lays on Chiaki's lap hugging her while playing Chiaki plays video games. This represents their relationship well since they would both care for eachother.
It is imagined that they would play video games together and cosplay together. Tsumugi would cosplay characters from Chiaki's favorite video games. Since they both are fans of videogames it also imaginable they would have conversations about this topic. They would supposely have video game slumber parties, such as the one Chiaki and Maki had in Danganronpa S. In conclusion, though this ship is not that popular in the Danganronpa fandom, it will never lose its loyal lovers.
- Tsumugi/Chiaki tag on AO3
- Tsumugi & Chiaki tag on AO3
- Hashtag Tsumugi x Chiaki on Instagram
- Both of them have talents relating to fandom.
- Tsumugi cosplays as Chiaki during Chapter 6 of NDRV3.
Shironamatsu refers to the two and Kaede Akamatsu