In The Dawn of a New Era!, Maru made her debut at Metal Bey City's Bey-Park. Using her laptop, she was scanning competitors Beys in the Zero-G Stadium to see which was most effective. She took an interest in Zyro Kurogane when he arrived and was amazed by how powerful he was.
In Zero-G Battle!, Maru was featured as one of the spectators of the "Zyro Kurogane vs Shinobu Hiryūin" battle. During the battle, Madoka appeared and was amazed by the power of Samurai Ifrit W145CF. After Zyro's defeat, and being told by Madoka to keep an eye on him, she followed Zyro to Benkei's fast-food restaurant, Bull Burger, where she agreed to help Zyro train, alongside Benkei.
Maru's name has multiple possible origins:
The word "Maru" can be romanised to "Mal" and translated from French and Spanish to mean "bad".
"Maru", is also Japanese for "Round" or "Circle".
Maru is the only Beyblade Mechanic who does not own her own Beyblade.
The fact that Maru calls Madoka "Chief" or "Chief Madoka" could be a reference to the original Beyblade series as Kenny (who was a Beyblade mechanic in the series), was called "Chief" and his real name wasn't found out until later in the series.
Maru can be the younger counterpart of Madoka Amano.