Sayaka Yumi is one of the main supporting protagonists of Shin Mazinger ZERO alongside Minerva X. Similar to previous series, she is the love interest of Koji Kabuto and has piloted three robots in the entire series.
Appearance
Sayaka's pilot suit for Artemis A.
Sayaka is an attractive teenage girl of average height and build. She has dark brown hair, wears a pink hairband, and has brown eyes. While her clothes vary, Sayaka is usually seen in her school uniform and a variety of pilot suits. Her first pilot suit was a white jump suit with a matching helmet with a clear visor. Her second was a pink and white blazer with a matching helmet and a white skirt. Her final suit is greatly reminiscent of her MazinSaga counterpart's: a rather revealing thin black number that covers her private areas but exposes the rest of her bare body, and also features ports for cords. When not docked in, Sayaka wears a long white coat over this suit.
Personality
Sayaka takes more after her counterpart from the original anime, tough and independent, yet she can be nice and sweet when she needs to. She is very close with Koji after their first meeting in high school, which started off as a sibling-like bond with the occasional arguing and eventually developed into feelings of romance. As such, Sayaka gets extremely angry or jealous when Koji is giving attention to other girls or when those girls show closeness to him, to the point of physical retaliation on Koji.
Abilities
Sayaka is a highly capable pilot, able to pilot three different robots with complex controls in a relatively short amount of time. Sayaka is also good at studying and athletics, and, while having difficulty fighting certain enemies, she often pulls moves to punish Koji when she believes he is two-timing.
History
Sayaka's Venus A
Sayaka's Artemis A
Pre-Minerva
Sayaka was with Koji in most realities where the Mazinger Z was found but lost her life either by Juzo Kabuto or as a casualty from battle. In the present reality, Sayaka was with Koji where Dr. Kabuto actually willingly gave Z to Koji and joined him in battle with Aphrodite A. During the Mazin War, Sayaka was given the Venus A to fight in. While the Mazinger Army managed to destroy all Mechanical Beasts, Venus A and most of the Army was destroyed. Sayaka however survived managing to get Venus' Pilder out in time. She however found Koji's body dead and brought him back to the Photon Power Laboratory after the giant Photon Barrier was put over Japan. Koji was revived as a cyborg and Sayaka continued to fight alongside him and Z with Aphrodite.
Minerva X's Advent
Sayaka was in battle with Koji against Mechanical as Koji was shedding tears of relief after encountering the memories of her death in another reality. She was also present when Minerva X transferred to Koji's class and was jealous when she asked Koji to meet her after class before the Gamia Q walked in and also asked for Koji. Sayaka tagged along with Boss to spy on what's going on between the groups. When the Gamia attacked, Sayaka helped fight them off before Shiro showed up and destroyed the last Gamia as well as reveal that Minerva is an android. As Koji left with Minerva joining him on the Pilder in an embarrassing fashion, Sayaka got jealous before leaving to pilot Aphrodite A.
When she tried to contact Koji, Sayaka misinterpreted the bumbling he said over the radio, thinking he was having a moment with Minerva before angrily dashing out on Aphrodite. An enraged Sayaka came as backup to fight the Mechanical Beasts, effortlessly destroying them before she was caught by Baron Ashura who demanded that Koji surrender and Minerva follow orders. However, Minerva's programming made her refuse and Sayaka was freed as Mazinger fought Ashura. Sayaka thanked Koji and Minerva but was weirded out when Minerva showed her affections for Mazinger Z.
A few days in and Minerva was fitting in with the others even after Koji and Sayaka revealed her secret as Dr. Hell's recreation. When Koji was invited to a concert as a special guest with Mazinger, Sayaka argued with him about being needed or not despite Aphrodite's repairs showing progress. Koji only pointed why she couldn't before leaving. Minerva then spoke with her about her feelings for Koji which Sayaka tries to deny but later confesses she does like Koji. At the concert Sayaka is with Shiro, Boss, and his gang in crowd as Honey Kisaragi introduces Koji piloting Mazinger Z. Soon the events of the Mazin War are shown through a dramatization before the Underground Empire starts their attack on the Photon Barrier and Sayaka prepares for battle.
As seen on Super Robot Wars X-Ω
After some help from Minerva, Sayaka was given a new robot in the form of Artemis A. However, she found her pilot suit to be very embarrassing. As Iron Cross and Iron Masks attempt to attack the Photon Lab, Sayaka confronts them in the Artemis, taking out a portion of the army. However, when she witnesses Count Brocken with her former comrades Lori & Loru turned into Iron Masks, Sayaka steps out of Artemis when Brocken threatens to kill them. But once outside, Sayaka destroys the brainwashed Lori & Loru before striking at Brocken, choosing to destroy the abominations that were once her friends rather than let them live as slaves.