Frieren

Himmel is the relationship the rest of her story hangs on. He understood her despite the chilly exterior. Himmel seemed to understand that Frieren's distance was not the whole of who she was. Rather than demanding that she change, he repeatedly drew her attention toward the people around her and the importance of remembering those who had died. He encouraged her to hold on to the memories of people she had lost rather than treating their absence as a reason to forget them. His actions also leave a legacy that Frieren encounters long after his death: the party's statues and the rewards he arranged to remain accessible far into the future. Their differences shaped each other: Himmel's instinct to connect with people gradually influences the way Frieren understands kindness, remembrance and human bonds. Years later, Frieren takes Fern on as her human apprentice at Heiter's request. That makes the new journey a direct consequence of the old one, not a fresh start.

Everything changes when the former Hero Party meets again for a viewing of the Era Meteors and Himmel later dies of old age. His funeral forces Frieren to confront how little she understood the man she had travelled with for decades, and the realization overwhelms her. Her regret becomes the emotional reason for the journey, pushing her to understand people in a way she had failed to do before. As the journey develops, Frieren sets her sights on Aureole, the legendary resting place of souls, hoping it will give her a chance to speak with Himmel once more. Himmel gives Frieren a ring featuring the mirrored lotus, a flower associated with eternal love. Frieren does not initially understand the symbolism, but she continues to treasure the ring long after his death. He keeps surfacing later. When an Einsam exploits her memories, it takes Himmel's form, showing how deeply he remains connected to Frieren's emotional world decades after his death. CBR interprets Frieren's later reflections as her gradually recognizing the depth of Himmel's feelings, and suggests that her own feelings for him may have been romantic as well. It reads her restrained response to that realization as evidence of emotional resilience.

The big dispute is what Himmel actually was to her. TV Tropes categorizes Himmel as a ‘Morality Pet’ and ‘Defroster’ for Frieren, reflecting the fan interpretation that his influence helped draw her out of her emotional reserve. That is a fan-edited source, so take it as interpretation. The relationship is also read differently by fans and critics: some interpretations leave the romance ambiguous, while CBR takes a more explicitly romantic reading of Himmel's feelings. The ring keeps both camps alive, because she cherished it without knowing what it meant. A second argument is whether her late understanding makes her tragic or admirable. CBR's case is that it makes her an unusually strong fantasy protagonist, since she grasps her mistakes too late but still learns from them. I'd say the series wants both readings at once. Her grief carries extra weight because she only begins to understand what she had taken for granted after it is too late.