Tenran no Memento

Our main character is a lethargic and cool high school student named, Akashi Chika. Chika spent his boring day-to-day life peacefully, however he has this dream that he often see in his sleep. It was a dream about a girl, a very neat and clean girl wearing kimono–. Without even knowing this girl’s name, Chika can’t help but to feel a nostalgic feeling towards her.
While he’s living his daily life with this matters still in his mind, somewhat grotesque being, completely out of this world appeared!! This incident fundamentally overturns Chika’s ordinary days, and he starts to recall his past memories which have been sealed.