Sanrio Timenet: Kako Hen and Mirai Hen

Sanrio Timenet: Kako Hen and Mirai Hen (Japanese: サンリオタイムネット 過去編, 未来編), literally Sanrio Timenet: Past Edition and Sanrio Timenet: Future Edition are monster-battling games mainly developed by Imagineer for the Game Boy. The games support the Game Boy Game Link Cable; which can be used to battle with other players and exchange information. Pictures of monsters and Sanrio characters met in the game can be printed using the Game Boy Printer.

Packaged with the games was a 'campaign' sheet where players could send for the illusory monster Stardust.

Story
Time was flowing properly in the world of Timenet, the home of the Old Man of Time, thanks to the Pillar of Time which is responsible for the flow of the past, the present and the future. However, due to the work of someone, the Pillar of Time was broken into small pieces and the world was divided into the past and the future.

The protagonist receives an email from the Old Man of Time, who explains the situation and requests that he or she helps save the world of Timenet by collecting the Time Fragments, before the flow of time is permanently lost.

The Old Man of Time asks the player for their name and the name of a friend, who is the opposite gender to the player. He/she will race the player to change the world of Timenet back to its original state, and will act as the player's rival at various points in the game. Soon after, the Old Man of Time takes the player to the world of the past (Kako Hen) or future (Mirai Hen). For some reason, the protagonist can hear a girl exclaim "help me" while travelling…

Gameplay
As either a male or female character, the player travels the world of Sanrio Timenet battling with monsters. Monsters can have up to four moves and each move requires Energy points. Moves have a variety of different effects, including dealing damage and afflicting status problems. If a monster uses a move and doesn't have enough Energy, the move will be used but health points will be used instead of Energy points.

Players can collect more monsters with items called Get Cards and up to six monsters can be held at a time. If the player obtains more than six monsters, a monster will be sent to the Pillar of Time and can later be withdrawn from a Computer or Mobile PC.

The Old Man of Time gives the player ten Get Cards to begin with, but more can be purchased from a shop. Later a Digital Camera can be obtained. The Digital Camera is basically an item like a Get Card that can be used infinitely and must be assembled from three Digital Camera Parts.

If the player obtains a monster and the Pillar of Time is full, an existing monster must be released from the Pillar of Time to hold it there, though the player may also release a monster immediately if they find themselves in this position. It is possible to release monsters in the Pillar of Time at any time using a Computer or Mobile PC.

The goal of the games is to help save the world before the flow of time is permanently lost. The player must fill up the Pillar of Time to 100% by collecting 161 monsters and must also collect watches. In their quest, they must travel to the future (Kako Hen) or the past (Mirai Hen) using the Time Ladder but after beating the game, they can no longer time travel. Depending on whether the player is in the past or the future, the names of places are different as well as monsters and which characters appear.

Near the end of the game, the player finds out the identity of the villain who destroyed the Pillar of Time and confronts her on Mars.