Masato Shikibu hailed from Iwate Prefecture, Japan, the son of a wealthy arms manufacturing company president. Defying familial expectations and his father's wishes, he pursued a military career, entering the academy as a sixth-team trainee, a decision reflecting his independent streak and rejection of his father's profession.

As the youngest member of the Cyber Beast Force (Jyusenki Tai), Masato compensated for his relative lack of combat experience and occasional immaturity with strong emotional resilience and spirited determination. His energetic personality often provided comic relief during operations, yet his fighting spirit proved crucial for motivating teammates in dire situations. He maintained a close friendship with Laura Sullivan, an orphan rescued by the team, and her dog Becky.

Significant character development occurred during the OVA "God Bless Dancouga," when Masato's father was killed during an engagement involving a Muge Empire survivor. This event underscored the personal toll of the conflict, despite the pair's strained relationship stemming from Masato's disapproval of the arms trade. Demonstrating emotional fortitude, Masato continued his missions without prolonged hesitation.

Following the war against the Muge Empire, Masato transitioned to civilian life alongside his wife, Laura Sullivan. He became a teacher at Gosha Academy, maintaining ties to his past through this educational role.