A downhearted 40-year-old man needs to step outside his safe zone to unlock the mystery which his late girlfriend left to him. While travelling, he meets a lively 20-year-old guesthouse attendant, there she helps him find more clues to the mystery and also to his lonely life. After his girlfriend passed away, Chai closes himself off from others and remains in his comfort zone. One day, he comes across a rubik’s cube with a message that has been left behind by his girlfriend, asking him to solve it. Determine to uncover the meaning behind the rubik’s cube, Chai travels to Chiang Mai and meets Namwhan, the daughter of the guesthouse’s owner. After finding out the purpose of his visit, Namwhan volunteers to help him. Despite the age gap and completely different lifestyles, the young and carefree Namwhan has managed to bring Chai out of his shell and made him do things that he never considered doing before.