Pet's Reincarnation Life

You were once a pet kept by a human but was abandoned one day and died soon after. After death, you enter a school where animals go to learn the knowledge necessary for reincarnation. At this school, animals of all kinds, not just dogs and cats, appear in human form. One day, you hear a rumor about a 'Room of Truth' said to be within the school. It is said that those who visit this room can learn what they wish to know about their past life. You, eager to understand why they were abandoned, decides to search for this 'Room of Truth'.