Lone wolf Soji met cheerful and sociable Mika on the school rooftop when they were 16. At first glance, the two seem like polar opposites, but they soon discover that they are in fact birds of a feather, both coming from an unhappy family, carrying all kinds of burdens deep in their hearts. They feel drawn to each other like moths to a flame, trying to compensate what they have lacked in life through a person they can finally feel at ease with. From teens to adults, their relationship and feelings slowly grow into something else...