YumiHisu

Yumikuri is the femslash ship between Ymir and Historia Reiss from the Attack on Titan fandom.

Canon
Ymir and Krista both enlisted in the 104th cadet training corps. The two of them developed a close friendship and Ymir was romantically attracted to Krista, sometimes referring to her as 'sweetie'.

Despite her normally cold and apathetic demeanor, Ymir cared deeply about Krista and even helped her graduate in the Top 10 so she could live safely in the Interior as part of the Military Police.

Ymir saw through Krista's 'good girl' act and encouraged Krista to embrace her true self and be proud of it. This inspired Krista to reveal her true name, Historia Reiss.

When they were surrounded by titans Historia told Ymir that, as long as they are together, she is not afraid.

After Eren utilized his titan-controlling ability, Ymir figured that Historia would be safe behind the walls and this gave her a sense of peace, allowing her to willingly lay down her life to pay back the debt she owed Reiner and Bertolt.

Fanon
Considering the pairs interactions, it is possible that a reciprocated emotional relationship existed. However, the lack of canonical reciprocation on the part of Historia means that the pairing is often substantiated by readers and viewers making assumptions on the part of the characters that stand contrary to their canonical depictions. The two of them were likely more affectionate with each other than we got to see, but there is no on-screen or on-page romantic interactions to support this and we have no reason to believe that the aforementioned affection would have been romantic in nature.

Fandom
FAN FICTION
 * Ymir/Historia tag on FanFiction.net
 * Ymir/Historia tag on FanFiction.net

TUMBLR

Trivia

 * Historia Reiss's alias is "Krista Lenz".
 * The creator of the series, Hajime Isayama, said in Animagic Con in Germany 2014, that the pairing were in fact a couple.