Anika's dad and Senku's adoptive father, Byakuya Ishigami, have been buddies for years, so when Anika's family moved to Japan when she was in elementary school, the dads were quick to get their kids to befriend each other. It was hard to get them to be interested in being each other's friend at first, Senku focusing on science and making rockets, and Anika more interested in gymnastics. However, slowly but surely, the two little kids became friends. Anika would help Senku with his science experiments, and Senku would watch Anika compete in the Little League's gymnastics competitions. The four kids would often hang out with each other. Taiju, Yuzuriah, Anika, and Senku would always find themselves in some form of trouble, whether it be Senku's rockets exploding midair in the park or Taiju thinking he could do a handstand longer than Anika and somehow getting hurt. Somewhere along the line, Anika caught feelings for the emotionally constipated scientist, and one day in high school, Anika was walking home with Senku (they live close to each other). As casually as possible, Anika states that they should date at this point because they spend so much time together, and in response, much to Anika's surprise, Senku simply agrees. Now we navigate the life of the couple, Anika, a competitive gymnast and athlete, and Senku, a scientific genius who has no athletic bone in his body and has an interesting way to show he cares.
