As a member of the Eagle Union, Atlanta is the eldest of the Atlanta-class cruisers, and the older sister of San Diego. Compared to her other younger sisters, Atlanta is more grounded, and is constantly trying to mend matters caused by her younger sisters' randomness. She tries to keep her place as an older sister, but sometimes she misses the mark in doing so. She decides to follow San Diego after hearing that she's going to participate in the Joint Military Exercise.
During the party, Atlanta asks how one should approach their younger sister. Will Atlanta get proper advice from Souryuu and Lexington?