Beet J. Stag (ビート・J・スタッグ Bīto Jei Sutaggu?), or simply "J", is the beetle-type Buddy Roid partner of Masato Jin (Beet Buster). He can also become Stag Buster (スタッグバスター Sutaggubasutā?), part of the second set of Go-Busters to join the team.
The "J." stands for "Jueki" (ジュウエキ?), which means "tree sap".
Beet J Stag is a humanoid Buddy Roid capable of defense and combat. Underneath his outer Buddy Roid shell is the humanoid form of Stag Buster. His armor becomes the Beet Buster suit for Masato, if they transform together. If Masato is the only one that is transforming, J. is able to send duplicates of the golden parts to trigger Beet Buster's transformation. Similarly, if J is the only one transforming, the excess parts are cast off of his body, and seem to vanish.
- Morphin Blaster
|“||It's Morphin' Time!||„|
|~ Transformation announcement|
Stag Buster/Silver Stag is the Go-Buster persona for "J". He achieves this form when he casts off his golden Buddy Roid parts, retaining his arm braces and shoulder pads, which become more streamlined and change to a metallic blue. Once the Buster suit is revealed, his head is revealed as a hollow Go-Busters helmet, which is "sealed" by the visor during the transformation.
- Morphin Blaster
PersonalityBeet J. Stag is a living testament to Masato Jin's belief that quirks make machines more interesting. J's "quirk" is that he likes appearing cool, though he has a habit of always standing in the way of Masato, which greatly annoys his creator and partner. He is also a self-proclaimed egotist, appearing to have no concerns except for his own.
However, underneath it all, J holds Jin in high enough regard that, should harm come to him, J would be relentless protecting him. He even once appeared to go 'rogue', when he discovered that a particular 'Messiah Card' contained the backup data that could fully restore Jin, protecting the Metaroid who carried it, while holding the Go-Busters at bay. He even went as far as threatening to destroy Jin's avatar, for the sake of getting the data, counterintuitive as it may be.