There was a Cute Girl in the Hero's Party, so I Tried Confessing to Her Episode 13: I Tried Being in a... with My Crush

The story opens with a stern Knight contemplating a wanted poster depicting a figure resembling the Black Lightning Swordsman. Yuuki, standing with Rael and Kleiman, is questioned about this mysterious 'Blue Flame Knight'. The group seems to be trying to understand the commotion caused by this new, disruptive hero. It sets the stage for a classic case of mistaken identity, or perhaps, a copycat.

Kleiman recounts the 'good deeds' of the Blue Flame Knight, showing blurry flashbacks of him 'helping' an old woman, finding a lost cat, and assisting a blue demon with planting. However, Kleiman quickly clarifies that these acts are far from helpful. Flashbacks reveal the Black Lightning Swordsman's clumsy interventions, like breaking a crate, returning the wrong cat, and destroying a plant's roots. This establishes a comic, yet serious, problem for the guild.

Kleiman, exasperated by the overtime and damaged guild reputation, orders Yuuki to capture the troublesome Blue Flame Knight. Yuuki initially protests but agrees, stating it concerns the Black Lightning Swordsman's reputation. He also admits a desire to distract himself from thoughts of Cecilia. With a determined expression, Yuuki dons his Black Lightning Swordsman mask, transforming into the hero ready to solve the problem.

Yuuki, disguised as the Black Lightning Swordsman, and Rael patrol the town, with Kleiman's internal monologue revealing their plan to distinguish the true hero from the imposter. Yuuki meticulously rectifies the Blue Flame Knight's past blunders, transforming sand into a sturdy pot for the old woman and retrieving the little girl's beloved toy crocodile. He even ensures the blue demon plants his herb correctly, carefully rebuilding the Black Lightning Swordsman's reputation and the guild's trust.

Alone with Rael, Yuuki removes his helmet, revealing his frustration and sadness over Cecilia's impending arranged marriage. He apologizes to Rael for his distraction, feeling inadequate because he believes Cecilia sees him as 'just a demon'. Rael offers gentle reassurance, stating that Cecilia is only truly lively when she is with Yuuki, prompting a flicker of hope and resolve in Yuuki.

Inside the mansion, Cecilia is worried, learning of Yuuki's wounds and fearing his perception of her due to the arranged marriage. Mikana reassures her of Rael's devotion, but a maid interrupts with news: the Blue Flame Knight has reappeared. Cecilia, now donning a wide-brimmed hat and glasses for disguise, confronts the chaotic 'hero', accusing him of damaging the true Black Lightning Swordsman's reputation. Her fierce loyalty shines through.

Yuuki, as the Black Lightning Swordsman, makes a dramatic entrance on a rooftop, much to Cecilia's surprise. When she affirms her belief in his consistent good work, Yuuki delivers a comically elaborate 'chuunibyou' challenge to Soliel, the Blue Flame Knight, to the utter confusion of Cecilia and the crowd. The two 'heroes' then leap to the rooftops, ready for a public spectacle, with Cecilia declared the Black Lightning Swordsman's 'partner' by Rael.

On the rooftops, Yuuki and Soliel engage in a high-flying battle. Yuuki playfully reveals that Soliel is his 'idol' but declares he will surpass him. Their clash is punctuated by Yuuki's proud declaration of his 'noble chuuni spirit' and commitment to living honestly. After the duel, Cecilia gently chastises Yuuki for his theatrics, leading him to confess his insecurities and how he imitated the Black Lightning Swordsman. Cecilia comforts him, urging him to use his power for himself.

As Kleiman and the guild members close in, Yuuki (as the Black Lightning Swordsman) sweeps Cecilia off her feet, literally, leaping from the rooftop to escape. They soar through the night sky, creating a breathtaking display of fireworks, leaving Soliel and the others behind. Landing atop a bell tower, Yuuki removes his helmet, his true identity now revealed to Cecilia amidst the romantic spectacle.

On the bell tower, Cecilia recalls her initial fear upon meeting Yuuki and contemplating death. Yuuki, now earnest, expresses his newfound desire to live, attributing it to the joys in his life. Cecilia reflects on how Yuuki has positively influenced everyone around him. She admits feeling a sense of freedom when with him, embracing his 'chuuni world.' Inspired by her steadfast presence and her words, Yuuki then confesses his love, asking Cecilia to wait for her answer regarding the arranged marriage.

Yuuki is seen waiting for Cecilia, while Rael confirms that Cecilia has refused the arranged marriage. Simultaneously, Cecilia arrives at her mansion to meet Soliel, now in a formal suit. He reveals his awareness of her affections for the Black Lightning Swordsman, stunning Cecilia with his perceptive, playful taunt. Soliel's departure leaves Cecilia in shock, hinting at a deeper connection between him and Yuuki.

Cecilia finally joins Yuuki in the gazebo, explaining that Soliel is his younger brother and that she needed to clarify the situation to his family, which caused her delay. Yuuki reflects on how he'd hoped their time together would last forever. With renewed determination, he reaches out to Cecilia, confessing his love and asking her to be with him. Cecilia, blushing, reciprocates his feelings, and they officially become a couple, sharing a happy, intimate moment.