27 year old Adachi Momoko lost both her parents in an accident when she was in third year high school. She then gave up going to college and has been working at a home centre for the past nine years while supporting her three younger brothers who are now 20, 17, and 14 year old respectively.
Kazuki Suzumoto is divorced and he lives with his 15-year-old son Kouki. Kouki is in a susceptible time. The father feels guilty about his son. Kouki then fails his high school entrance exam. In the spring of the following year, Kouki barely passes his high school entrance exam. Kouki mentions to Kazuki that he likes his father's lunch box. The father and son make a promise to each other. Kazuki promises that he will make a lunch box everyday for Kouki. Kouki promises that he will never skip school.
Okawa Yuka is living out the daily motions of life but doesn't understand her reason to keep living. After a confrontation with a co-worker, she decides to end it all but fails when she stops herself from squishing a cicada. That cicada returns the favor by transforming into a man, named semi, for seven days because he thinks it will make her happy. The downside is, he has no idea how to live as a human.
