Kamen Rider Zangetsu Takatora Kureshima is continuing preparations of Project Ark, which would mean the salvation of humanity at the cost of numerous lives. Takatora's resolve in seeing this through is put in question after a conversation with Kota Kazuraba. Meanwhile, Yggdrasill's Kurokage Troopers are being assailed by an unknown Armored Rider. The caretaker formerly employed by the Kureshima family, Tōka Akatsuki, makes an appearance. Being raised by a strict father, Takatora's only support during his childhood years was Tōka. Both are very happy to meet again, but on a depressing note as the Kureshima brothers learn that their father had died. However, the mysterious attacker, using the Ringo Lockseed, leaves Sid injured and Yoko to be on the defensive. The mysterious Rider sets their sights on Mitsuzane Kureshima and Takatora loses his Melon Energy Lockseed as a result. While searching for clues, he uncovers the truth of his father's past and learns that the people at Zawame Child Care Facility were subjugated to lethal experiments to allow passage into Helheim. Among the list of people in the orphanage is Tōka and Takatora puts one and one together. Confronting Tōka while using the Watermelon Lockseed given by Ryoma Sengoku, he tells Tōka that he will continue to do what he believes in, even if he lays down his life for it. He defeats Tōka after he regains the Melon Energy Lockseed. However, he is unable to kill Tōka due to their past. Tōka retreats back to the abandoned orphanage, after being spared by Takatora and don't understand that why a good man like Takatora carries a name of Kureshima. Shortly, Tōka experiences the side effects of the Ringo Lockseed and learns that Ryoma Sengoku was also raised at the orphanage before being killed by Ryoma, who promptly retakes the Ringo Lockseed. After cleaning the Kureshima residents with Mitsuzane, Takatora start to think about Kota's word about saving humanity without sacrifices, and perhaps he may use one of Kota's heroic influence a bit.
Kamen Rider Baron While Kaito Kumon hunted for the Overlords during his alliance with Ryoma Sengoku, a foreign prince named Shapool visits Zawame as part of an inspection. Shapool finds Kaito to be identical him, having the latter sedated so he can switch places with him. While Kota and the Beat Riders were flabbergasted in "Kaito" actually smiling before he takes Mai to Charmant, the real Kaito finds himself taken by a group led by Shapool's butler Alfred. Alfred then deduces Kaito's identity, contacting to Oren to take care of him. By the time Kaito finds Shapool, the two are attacked by Alfred who threatens to kill Shapool while transforming into Kamen Rider Tyrant. Kaito protects Shapool and learns of his story, as well as sharing his own story with the prince. After finding out that Alfred has taken Zack, Kaito goes after Alfred. As both were transformed and battled each other as Baron and Tyrant respectively, Tyrant unexpectedly corrupted by the Energy Lockseed possessing Helheim's manipulation and became an Overlord Inves. Yoko later came in and gives Kaito the Ringo Lockseed she took from Ryoma. Though warned that it could turn him into an Overlord, Kaito uses the Lockseed to fight back as Baron Ringo Arms and defeats Tyrant with the Cavaliend Rider Kick before destroying the Ringo Lockseed. In the end, Shapool writes a letter to thank Kaito for saving him from Alfred's threats and taking what Kaito has taught him, to believe in friends and to fight for what is right, before he leaves Zawame City for reuniting with his father. Kaito went to his parents' tomb at a cemetery, and later walks out as the flowers were left onto his parents' tomb. However, though he did not become an Overlord at that time, the event is still within Kaito's future.
Cast ;
Kamen Rider Zangetsu • : • : • : • Takatora Kureshima (teen): • Mitsuzane Kureshima (child): • Tōka Akatsuki (teen): • : • : ;
Kamen Rider Baron • , : • : • : • : • : • : • : • Kaito's father: • Kaito's mother: • Kaito Kumon (child): ;Both
Kamen Rider Zangetsu and
Kamen Rider Baron • : • : • : • : • :
Theme songs ;
Kamen Rider Zangetsu insert theme • "Lights of my wish" • Lyrics:
Shoko Fujibayashi • Composition: Ryo (of
defspiral) • Arrangement: Ryo (of defspiral),
Junichi "IGAO" Igarashi • Artist: Mai Takatsukasa (Yuumi Shida) ;
Kamen Rider Baron ending theme • "Unperfected world" • Lyrics: Shoko Fujibayashi • Composition & Arrangement: Ryo (of defspiral) • Artist: Kaito Kumon (Yutaka Kobayashi) ==
Gaim Gaiden: Kamen Rider Duke/Kamen Rider Knuckle==