Summer Vacation Free Research 'Engagement Annulled Observation Diary' is a poignant Japanese web novel that delves into the intertwined lives of siblings and childhood friends. The narrative follows a person recounting the story of their brother and his childhood friend, whose engagement is abruptly annulled by her fiancée. With themes of drama and romance, the novel explores broken engagements, European ambience, and heartwarming moments, making it a captivating oneshot read filled with intriguing characters.