Beautiful and well-behaved high school girl Mika (played by Yui Aragaki) accidentally lost her mobile phone, which was picked up by Hiroki Sakurai (played by Haruma Miura) and returned to her in the library. However, Hiro deleted all the contact information in Mika's mobile phone, and called Mika day and night throughout the summer vacation, chatting with her. Although they had never met, Mika's heart had gradually opened up. After they officially met at the beginning of school, the two fell in love and tasted the forbidden fruit. Soon, they were retaliated by Hiroko's ex-girlfriend, which led to tragedy. Mika was heartbroken, and Hiro's strong protection helped Mika get through this difficult time. Soon, Mika became pregnant, and Hiro asked her to give birth to the child. The two met with their parents, and Hiro's sincere and resolute request was understood by everyone. But the tragedy happened again, and Mika lost her child. A bigger blow came after the start of the second year of high school, when Hiro proposed to break up. Because she couldn't get a definite reason, Mika waited for a long time before gradually starting a new life. She fell in love with You, a gentle boy from Qing University, and went to college. Everything seemed to be getting better. On Christmas of that year, You proposed to Mika, but soon after, Mika learned the sad secret that Hong had been hiding from her... Everything was broken, and Mika knew that the one she loved the most was still Hong.