Tsukiko is Tanpopo's first friend at Meio Academy. Despite her innocent appearance, she initially isn't very kind. However, she undergoes a positive transformation by the end of the manga. She has ambitions of marrying into the Kugyo family and sets her sights on Koki.
Eventually, Tsukiko overcomes her feelings for Koki and steps aside, allowing Tanpopo to pursue him. Afterwards, she seems to develop some affection for Aoi, though this is not explicitly confirmed in the official storyline.
Source: Wikipedia








