Kourin Tatsunagi stands as a central figure in Cardfight!! Vanguard, one of the three Tatsunagi sisters alongside Suiko and Rekka. Together, they operate the card shop PSY and perform as the idol group Team Ultra-Rare. Her appearance features long blonde hair, often styled with half tied on the left side, and striking green eyes. She typically wears her Miyaji Academy school uniform or her Team Ultra-Rare attire. Initially disciplined and no-nonsense, Kourin exhibits a serious offstage demeanor, distinct from her idol persona. She enforces strict standards for the Miyaji Academy Cardfight Club, demanding prospective members defeat her in a cardfight to prove dedication, reflecting her pragmatic nature. She gradually forms strong bonds with club members, particularly Aichi Sendou, whom she deeply respects as a leader. External forces significantly alter her personality; under the "Reverse" state, she becomes cold and possessive, explicitly desiring to claim Aichi for herself. Despite this darkness, her core dedication to protecting others persists. She absorbs Link Joker's corrupting energy to shield Aichi from pain, accepting personal risk. Her background reveals she and her sisters were summoned by Takuto Tatsunagi, who sealed their original memories to enlist them as agents protecting Earth and Cray. This memory alteration means her recollections of Aichi and the Cardfight Club form her entire identity. Following Takuto's defeat, Kourin vanishes from public memory, with only Kai and Misaki retaining awareness of her existence. In season 4, she allies with the Quatre Knights to guard Aichi, utilizing a Link Joker deck to intercept opponents like Kai. During the sanctuary's collapse, she repeatedly absorbs Link Joker's miasma from Aichi, nearly consumed by darkness before Aichi rescues her. Post-crisis, she returns to Team Ultra-Rare, though subtle connections linger, such as Misaki wearing her hairband. In the V Series continuity, Kourin co-founds the Miyaji Academy Cardfight Club and faces a similar fate as a "Called Walker," destined for memory erasure after aiding Takuto. Her personality is noted as tsundere; she gradually cherishes her friendships despite knowing her impending disappearance. After the timeline corrects, she rejoins Team Ultra-Rare but experiences unexplained emotional ties to the club, exemplified by instinctively encouraging Naoki during a tournament. She later defeats Aichi in an exhibition match to become the club's honorary member, symbolically rebuilding their bond. As a cardfighter, Kourin employs multiple clans: - Season 1: Royal Paladins, centering on "Fang of Light, Garmore" and critical triggers. - Season 2: Angel Feathers, focusing on healing and stand triggers. - Season 3: Royal Paladins (Jewel Knights), using "Broken Heart Jewel Knight, Ashlei 'Яeverse'" while Reversed. - Season 4: Link Joker, wielding "Star-vader, Garnet Star Dragon" to lock opponent rearguards. - Manga: Gold Paladins, with "Raven-haired Ezel" as her ace. Her relationship with Aichi forms a recurring emotional anchor. She supports him through critical moments, such as gifting him "Incandescent Lion, Blond Ezel" in Singapore. Their connection deepens when she hears his tormented voice across dimensions, compelling her to reach him in the sanctuary. A pivotal scene during Link Joker's defeat underscores their mutual grief over her impending memory loss, highlighting their unspoken bond.