Yokuryū is the aerial combatant of the Dinoforce, a Decepticon subgroup commanded by Deathsaurus. As the team's sole flier, he shows little interest in effort or teamwork compared to his comrades. Yokuryū maintains an aloof attitude, completing tasks with minimal enthusiasm and barely meeting requirements. His primary motivation is pursuing an easy life, avoiding strenuous activity whenever possible.

Despite his lazy demeanor, Yokuryū possesses significant potential as an aerial warrior, capable of near-light speed flight. His semi-autonomous Pteranodon shell generates magnetic "nets" from its wings to immobilize foes. This enables his signature "Yoku-Pterano Fire" attack, where the shell ignites in high-heat flames for a high-speed ram. However, his reluctance to exert himself prevents these capabilities from reaching their maximum effect.

Years before the main conflict, Yokuryū participated in the Dinoforce's raid on a Mars research ship. The attack stole significant energon reserves and destroyed the vessel, killing nearly all aboard—including Jan's parents. The Dinoforce escaped before Star Saber arrived, leaving only the infant Jan surviving in an escape pod.

During Deathsaurus's campaign against Earth, Yokuryū undertook multiple missions. He joined the lunar energon raid, attacking a floating space station and lunar base until repelled by Star Saber. Later, during an ambush on Wingwaver, he followed Goryu's strategy to send the dino shells ahead to destroy the Autobot Galaxy Base while the Dinoforce fought the Brainmasters. When combined into the gestalt Dinoking, the team initially overpowered opponents but consistently faced defeat against Star Saber's forces.

Notable engagements include an assassination attempt on Star Saber at Jan's school, where Yokuryū provided aerial escape for the retreating Dinoforce. During a floating energy plant heist, he received a light "toasting" from Goryu for questioning the commander's deviation from Deathsaurus's plan. He also participated in tropical island training sessions and operations at the Ocean Exhibition amusement park and Neo Uranium Mine in Africa, contributing minimally due to his slack attitude.

In the Amazon jungle, Yokuryū performed long-range reconnaissance for a Decepticon energy stockpile base. After spotting disturbed birds, he fired indiscriminately into the jungle, causing multiple fires. He later used his shell to generate a windstorm over a river, exposing hidden Autobots. His single-minded pursuit of Blacker, however, allowed the Multiforce to evade detection.

Yokuryū's primary role culminates in the Dinoforce's combination into the gestalt warrior Dinoking, where he forms part of the combined entity.