|Game Debut||Danball Senki (PSP)|
|Anime Debut||Episode 01|
|Appears in||Game, Anime|
|Voice Actor||Hiroki Touchi|
|Relatives|| Takeshi Hiyama (deceased)|
Mami Hiyama (alive)
|Occupation|| Professor Yamano's Assistant|
Bar Tender (outside cover)
Veteran LBX Player
Seeker Informative (former)
|Affiliation(s)|| Seeker (former)|
|LBX:|| G Rex (Break Over)|
Kabuto (temporary for Ban's training)
Ifreet (Break Over)
|Achievement(s)||Legendary LBX Player|
'Ren Hiyama' (檜山 蓮 Hiyama Ren) is one of the support characters for Ban and his friends in Danball Senki. Later in the second half of the first season, it is revealed that he is mastermind behind the Kaidou android, taking the Innovator's plans for his personal vengeance. Thus, making him the true main antagonist of the series.
Hiyama has purple, spiky hair and usually wears a dark coat with a hoodie. He is medium sized for an adult and wears shades.
For most of the series, Rex's attitude is that of a calm, supportive ally for the Seekers. During his "fight" against the Innovators, he usually gives secret routes in companies and helps assist Ban and the others. Regardless of all that, Hiyama is actually evil who shot Kaidou Yoshimitsu and controlled the Saturn's flight to N-City.
He runs a coffee shop in Mysore called "Blue Cats." It seems that he is aware of the contents of the briefcase given to Ban and who gave it to him. He is actually a very strong LBX player called Lex (so it says at the back of is hooded jacket). He taught Ban Yamano an attack function that he could use in Artemis and he also participated in the tournament. Though, he lost to Jin Kaidou, Jin said that Ren actually just didn't take it seriously, and really planned to lose. And the next time they saw Ren was he was the one who killed Yoshimitsu Kaidou and build a Kaido Yoshimitsu android. He wants to build a new world by destroying N-City with Saturn but he was defeated by Ban and died in the Saturn.
- "Humans are not beasts. Humans are not gods. Humans are questions what is means to be human. Exactly what is "man" here for. Humans that have become too smart begin controlling and ruling the world, as if they were gods. Humans who obtain great power devour the weak and pay no mind to their acts of cruelty, as if they were beasts. At some point, those people who progressed too far forget what is like to be human. I wanted the world to think about this, about the way humans should be.", - Lex's message to the world.