From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
The Heavenly Realm (天来界, Tenraikai) is an ancient platform that is in geostationary orbit above Planet Earth and directly above Karin Tower. (For some time, Karin Tower and the Heavenly Realm are connected by Son Goku's Power Pole). Events occurring on Planet Earth are observed and battles in the universe sensed from this location.
Outside the Heavenly Realm
Hyperbolic Time Chamber
Main article: Hyperbolic Time Chamber
The Hyperbolic Time Chamber was featured prominently in Dragon Ball Z. It was in a different time dimension where a day outside was a year inside (or just one minute outside was just over six hours inside). It was used by many major characters, and Gotenks fought Super Buu in it. Piccolo destroyed the door during this battle in an attempt to lock Buu inside forever, along with himself and Gotenks, so it is impossible to get in or out of it now (unless it had been revived by the Namek Dragon Balls. However, Buu was able to escape by creating a portal by screaming at the top of his lungs, which Piccolo and Gotenks did after he escaped to let themselves out. Supposedly the room could only be used for up to 48 hours outside the chamber in one lifetime. If one were to break that rule, the doorway to the outside world would automatically vanish, thus trapping the trainee(s) inside for eternity. However, in Buu or Gotenks' case, they would simply bust out as they had done before, thus nullifying this effect. A popular misconception is that only two people can enter the room at a time. In actuality, there is no limit to the number of people that can enter, but there is only enough food inside for two people. Goten, Trunks, Piccolo, and Super Buu were able to be inside all at once, albeit for a short time, so in their case the shortage of food was not an issue.
Main article: Pendulum Room
The Pendulum Room exists as filler in both the Dragon Ball and Dragon Ball Z animes. Mister Popo stated that the past, present, and future was operated and controlled in this room. The main function of the Pendulum Room was to send one's, or people's, spirit through time to train. In the Dragon Ball filler episode "The Time Room", Goku was sent back in time to learn from Turtle Hermit's former teacher, Mutaito, about manipulating one's Ki. In the Dragon Ball Z filler episode "Pendulum Room Peril", Tenshinhan, Yamucha, Chaozu, and Kuririn went to a similar (or possible the same) room where their spirits were taken back in time to fight two Saiyans from the past, Shorty and Scarface. This room, or rooms, did not appear in the original manga.
In the Dragon Ball filler episodes "Quicker Than Lightning" and "Secret of the Woods", it is revealed that the Heavenly Realm had a teleporter or transporter machine that allowed Kami or anyone else to go wherever they wanted to on Earth. Kami was rarely shown using it, but the most notable case was in Dragon Ball Z: Dead Zone during the initial struggle against Garlic Jr.
Inside the Heavenly Realm
Divine Sage Realm
In Dragon Ball Z, the very bottom of the Heavenly Realm (where the Power Pole fit in) was connected to all the winds of the world. To get there, one had to go through a sacred area within the Heavenly Realm known as the Divine Sage Realm where the graves of the Kami of previous generations were located.
In Dragon Ball GT, it was empty. This was where Goku and Oob had their battle without harming Earth.
- Mister Popo (Assistant to the Kami of Earth)
- Kami (Former Kami of Earth before fusing with Piccolo)
- Dende (Current Kami of Earth)
- Piccolo (He resumes residence there after the events of the Cell Saga.)
- Son Goku (Trains at the Heavenly Realm for three years after the defeat of Piccolo Daimao and then returns between the events of the post-Majin Buu Saga and Dragon Ball GT to train Oob.)
- Oob (Trains here with Goku between the events of the post-Majin Buu Saga and Dragon Ball GT.)
- The Heavenly Realm is usually where the Z Warriors take refuge and where no villain can find them. The only villains to actually discover the Heavenly Realm are Garlic Jr., Super Boo, and Pilaf (in Dragon Ball GT).
- It is unknown what happens to the former Kami when the Heavenly Realm is destroyed by Super Boo. It is possible that they are within a different dimension, the portal of which is within the Heavenly Realm.
- The Heavenly Realm gets damaged during the fight against Garlic Jr. and the Spice Boys. Later, when Piccolo returns from the Hyperbolic Time Chamber to see the Heavenly Realm damaged by Super Boo (after turning everyone there into chocolate and eating them), Piccolo says, "Completely ruined... again!" He could not have said this if the Garlic Jr. Saga did not take place in the anime (as it is a non-manga event). Piccolo's line is evidence of the Garlic Jr. Saga being canon, which is the only other time the Heavenly Realm is damaged. It may have been damaged at another time off screen, however, such as in the initial fight between the Nameless Namekian and Garlic.
- When Planet Earth is restored to its original state with the Dragon Balls, as with every other place, the Heavenly Realm is wished back with no damage at all. It is possible, therefore, that the door to the Hyperbolic Time Chamber is also returned.
- During the Cell Saga, Bulma Brief reaches the Heavenly Realm by flying in a plane. Earlier in Dragon Ball, however, it is said to be impossible to reach even the top of Karin's Tower using any kind of vehicle other than a rocket ship.
- In "Lost and Found", Goku is going to ride his Kinto Un up to the Heavenly Realm to ask to revive Shen Long, but Karin tell hims that the highest the Kinto Un can reach is Karin Tower. This is probably because the Heavenly Realm is above the clouds and the Kinto Un is a cloud.
- During the Majin Buu Saga, it is seen that Goku's Power Pole is removed from the bottom of the Heavenly Realm.
- Black Star Shen Long's head is roughly the same size as the Heavenly Realm.