One More Time Machine?! Bulma Unveils a Mystery

Plot:

Bulma receives a phone call about one of her company's products from Capsule Corporation. She is sent a photograph of what appears to be Trunks' time machine that he travelled in. Trunks investigates this with the others only to discover that it is the exact time-machine that he came in but three years later in his world. He recognizes it because of the word 'Hope' that Bulma wrote on the time-machine. Kami realizes that the evil he felt four years ago wasn't the androids but it was the monster that travelled back in the time-machine.