Tsugumi is one of the characters from the anime Guilty Crown and is 14 years old. She is an excellent hacker who acts as the operator for the gureilla resistance group "Undertaker".
She is very brash and cheeky and speaks unreservedly even to the leader, Gai. Her catchphrases are: "Aye!" (roger), and "Ney!" (negative).
She is first seen standing infront of Shu right after Gai saves him and takes Fyu-neru away from him, leaving Gai and Shu alone. She is seen a second time, warning everyone of the enemies that were approching. She is seen later telling Ayase where her next targets were. However, Ayase asks her to find closer targets instead but Tsugumi (who is playing games while trying to find the enemy hideout) tells her that she was working too hard and her craft has had about all it can take. However, she doesn't listen and continues fighting. This is a mistake on Ayase's part as she is quickly defeated and nearly killed by Daryl. Tsugumi saves her from that by ejecting her from her craft. Later, Tsugumi teases Ayase because of how she reacted due to Gai's statement, saying her "heart soared to the top of the charts". Tsugumi is later seen at the meeting shouting "Aye-aye!" as the whole of the Undertaker cheers due to Gai's plan to rescue the hostages. After the fight commences, Tsugumi tells Ayase to take care of her 'babies' and after is seen watching as Gai offers Shu to join them. She later helps Gai hack into the GHQ's main system to block the security cameras, to help him save Kido. She is seen watching with everyone else in the Undertaker as Gai introduces Shu to them. Later, Tsugumi watches in amusement as Shu tells Ayase that he doesn't want to cause her trouble because she is in a wheelchair, only to get his butt handed to him afterwards. After Shu's mock battle, Tsugumi informs everyone that the Leukocyte was fired at Point Delta (the area where Gai was). Everyone in the room is worried that Gai is dead until they hear his voice. They regroup and fprm a plan to destroy the Leukocyte. Tsugumi tells Gai that they have 30 seconds before it struck Japan. However, Shu saves them by destroying the Leukocyte.