With the rise of Astro ND series, more competitor showed up alongside its growth. Among them the Rock Gaki TRACK series by Capital Company stood out the most, a series that aimed to replace the ND. 
Rock Gaki was built with the intention to introduce the next generation racing, Droid Racing (DR). 
Rock Gaki TRACK DAY-1 an android with a sturdy frame and high adaptability to its environment. As the first of its line
Rock Gaki was designed to be modifiable by any third party to acknowledge the creativity and skill of anyone and everyone. 
As the word of its creator professor L, "Imagination is limitless, I want everyone to be able to show their skills and not limit them by what I made."
Rock Gaki TRACK DAY - 1: As the first mech, its main colour scheme is blue in colour and it comes with a hand cannon. 
The weaponry is due to the reason that the next generation racing DR did not specify any penalty or punishment in assaulting other racers
thus any weapon that does not harm the audience or bystander are allowed. 

Rock Gaki TRACK DAY-1 equipment includes a transformable magnetize hoverboard (transformable between magnetize hoverboard and land cruising) and an emergency energy charging pack. 
Professor L insists that Rock Gaki TRACK DAY-1 have a humane trait and independent thinking to allow them to access and act according to their situation. 
Rumor have it, Professor L owned a personal model of Rock Gaki TRACK DAY-1 that is capable of travel long distance and able to perform action of its own thinking to help others that it met
and it causes the public to once thought Rock Gaki is not an android but a human, but the situation is dissolves after Professor L came out and made a public statement about it.

Unlike Rock Gaki TRACK DAY series, Rock Gaki TRACK NIGHT is made with the intention of being the security or law enforcer. And unlike the standard DAY series NIGHT is made by Dr W, a professor with the different point of view from Dr L, he believed that unmodifiable and secrecy to the tech is key.Thus, the company sees his point and agree to let him lead the team to build the security droids, which is known as Rock Gaki TRACK NIGHT. However, despite Dr W having different ideology, he did take inspiration from TRACK DAY and Dr L even gave him the authority to access the prototype of Rock Gaki. Due to this act, Dr W decided to begin his NIGHT series numbering 2, to show Dr L his appreciation on aiding his project. Rock Gaki TRACK NIGHT - 2: NIGHT series first product comes with red color scheme, and like the DAY seriesit comes equip with the same hand cannon and gear, with a difference of NIGHT hoverboard are made with stronger materialas its design allow it to be used as shield. And unlike the DAY series, NIGHT series are none modifiable by any third partyit is being set to retaliate according to the severity upon any unauthorized access. NIGHT also come equip with a night vision, to allow it to perform in dark situation such as nighttime. Since NIGHT was developed for security work purposes, it has the default setting of following the state law and/or the full ruling of DR race.They both have the same independent thinking as the DAY series, but are not as humane as DAY.