FutoKuno

FutoIku is a shipping of Futoshi and Ikuno from the fandom Darling in the FRANXX.

Canon
Futoshi and Ikuno have known each other since they were small children living in the Garden but they barely interacted with each other. When they are 14, they are assigned to the same FRANXX squad, with Futoshi paired with Kokoro and Ikuno paired with Mitsuru.

The two hardly interacted with each other until Episode 11, when Nana proposes a partner shuffle due to Mitsuru and Ikuno’s incompatibility. Futoshi initially says there is no reason for him and Kokoro to split apart because he promised to protect her forever. However, after Ikuno asks to try linking with Ichigo, Kokoro asks to try riding with Mitsuru, which came as a complete surprise to everyone, especially Futoshi. During a capacity test, Ikuno and Ichigo fail to connect and time out whereas Mitsuru and Kokoro manage to maintain a low but stable connection. As a result, Futoshi and Ikuno are paired together, and Kokoro and Mitsuru are paired together.

During their first battle as a pair, Ikuno sighs in irritation at Futoshi for getting emotional as he goes off to fight without Kokoro as his partner. However, the two perform really well together. They use Chlorophytum to hold the klaxosaur off while Kokoro and Mitsuru try to talk out Mitsuru’s problems and reconnect.

During the second battle at Gran Crevasse, they are part of the rescue effort to help Zero Two reach Hiro. However the passage leading Strelizia’s location is blocked off and they are cornered by VIRM soldiers on the other end. Ikuno and Futoshi go full power to blast open the passage but Chlorophytum deactivates. Futoshi is shocked to see Ikuno panting and her hair has turned white.

Despite Ikuno’s declining health, she and Futoshi take part in the galactic battle against VIRM and to help Hiro rescue Zero Two.

Ten years later, while Ikuno, who has aged into an elderly woman due to her retaining her accelerated aging process, Futoshi visits her with his new bread recipe. While he chats with her, Ichigo, and Naomi, he credits Ikuno for her research in keeping the parasites’ accelerated aging process under control, and she compliments his bread.

Fanon
This shipping is not all that popular due to that Ikuno is attracted to Ichigo and Futoshi was initially in love with Kokoro.