When the JFA got the word about Nana Mishima's return in Japan, Nadeshiko Japan's coach Mitsuhiro Gotou and captain Taeko Isshiki were sent at the Mishimas in an attempt to convince Nana to play for Japan. As Nana showed reticence towards the offer, Taeko openly challenged her before leaving. On the following day, Taeko was trying to cheer her teammates up after being down 0-2 at halftime against the American Women's League team, the Miami Hurricane, when Nana arrived for the second half. At first, Taeko was skeptical of how her new teammate could contribute, but then changed her attitude towards Nana after the latter helped Nadeshiko Japan completing the turnaround to defeat the Miami Hurricane. Taeko now fully trusts Nana in helping Nadeshiko Japan to reach a higher level.
Taeko has black neck-length hair. Her eyes, like her hair, are also black. She also has a good height at 172 cm (5 ft 7 in), which makes her the tallest field player for Nadeshiko Japan.
When off the field, she was seen wearing a pink hoodie with short sleeves, black pants and sunglasses in order to avoid photographers.
Her training track-suit consists of a black track jacket and trousers with two white strips on the side. When in training, she usually wears the official Nadeshiko Japan's training kit which consists a sky blue top and shorts. On one occasion, she was seen wearing a pink top under her black track jacket. While playing for the Nadeshiko Japan Team, she wears a blue football uniform with the number 10 printed on the back.
Taeko is a tough woman who demands no less than the best out of her teammates. She can challenge others by playing on their pride, but she also knows when to use a more positive approach to motivate the team. She is able to recognize soccer players just by looking at the muscles in the legs. Even outside of matches, Taeko is a very serious person in any aspect of her job as a representative of Nadeshiko Japan, whether it is in training or in a swimsuit photoshoot.
Initially, Taeko was skeptical of Nana's capabilities mainly because she didn't play on any team for a year and a half. However, after Nana displayed all of her skills as a scorer and a playmaker, Taeko started trusting Nana to become a leader for Nadehiko Japan.
Taeko and Mina appear to be good friends off the field.