I Cannot Reach You, Vol. 6 by Mika

Time rewinds to Kakeru and Yamato's elementary school days, when they first met each other. While their personalities are near-exact opposites, they grow closer with each day they spend together. Soon, Kakeru learns more about Yamato-that his father fell into a coma after an accident, and even about a certain secret that he's hiding...
Binding: Paperback / softback