ShibiSere

ShibiSere is the het ship between Serena Rinnen and Shibisu from the Tower of God fandom.

Canon
They met for the first time after the first Second Floor elimination test. After getting pushed back by Lero-Ro's shinsu wave, Shibisu tries to push through the wall of shinsu but can't. Serena sees him failing to pass through the wall and taunts him before failing to pass through herself as well, causing Shibisu to laugh at her. The two bicker back and forth, competing to see who could pass through first. They eventually pass the wall through pure stubbornness and force of will.

The two share a number of similarities, as they are both proficient in hand-to-hand combat, incredibly strong-willed, and stubborn. Compared to the other Regulars (their teammates), they are considered the weaker of the bunch since they do not possess any special powers or strengths. After passing the Shinsu Test, the two are seen high-fiving in the background, with Shibisu's teammate, Lauroe, napping in the foreground.

During the Crown Game, we can see that both characters are in separated groups (Serena teamming up with Lauroe and Ho, while Shibisu teamming with Anaak and Hatz), but they could finally meet again in the second round of the game which one her team and Serena fought against Ship Leesoo alongside Ho.

In the Last Examination, Serena and Shibisu are among those who attended Hoh's funeral. Later, even when it is revealed that she had failed the Position Test, Serena is still seen present at the celebration party thrown afterwards. However, as the others were getting drunk, it cuts to a scene of her walking away from the Tower. Shibisu notices and follows her.

Serena's inner dialogue reveals how poorly she thought of herself and how her "... life was filled with nothing but regrets." However, Shibisu shows up and the two talk for a while, the Scout being rather confused as to why Serena was leaving, and while Serena doesn't explicitly tell him about her past, she tosses him her favorite knife as a parting gift. As Serena leaves, she tells Shibisu, "Don't you dare die, Shibisu," before giving him a smile and then walking away.

Shibisu is uncharacteristically solemn after Serena leaves, and does not return to the celebration party.

Fanon
Even if it's not very popular, this ship it's known in the Tower of God fandom. The ship started since fans took a liking to their dynamic, friendship, and their closeness.

It is the most popular ship for Serena and the most popular het ship for Shibisu.

Fandom
FAN FICTION

Trivia

 * Shibisu and Ship Leesoo are different translations of the same name, with 'Ship Leesoo' being used more commonly among webtoon-readers and 'Shibisu' more commonly among anime-only's.