Hyakunichikan!!

High school student Shuuto had been eagerly anticipating a stretch of uninterrupted freedom. With his parents departing for overseas work, he envisioned a peaceful life where he could finally relax and enjoy the house entirely to himself. However, his dreams of an easygoing routine are abruptly shattered when he discovers an unexpected guest waiting for him inside his own home: a five-year-old girl. As it turns out, the child's mother is a colleague of Shuuto's parents who has joined them on the same international trip. Before leaving, she entrusted her young daughter to Shuuto's care for the next three months. Suddenly thrust into the role of an impromptu guardian, the teenager must navigate the overwhelming challenges of raising a small child while trying to maintain his studies and daily life. What was supposed to be a season of leisure quickly transforms into a chaotic yet heartwarming journey of responsibility and unexpected bonds. This complete edition also includes five bonus chapters alongside a concluding epilogue.