Although the two have been shown in the canon timeline, they have not interacted since Kokomi was absent while Sara led an attack with her troops. However, Sara does mention Kokomi in the passing when she first sees the traveler, saying "So you are the only one here? Hm... I thought I might get to meet your grand strategist." Despite Sara's army having many, many more soldiers, the resistance is able to hold their own due to the brilliant plans that Kokomi, their strategist, comes up with. It seems as though Sara acknowledges her intelligence, saying that she thought she'd be able to meet the person behind the plans.
Sara has a voiceline about Kokomi where she compliments her capabilities. She says that Kokomi is more proficient as a military strategist than a priestess and that her methods of waging war are almost unheard of. Sara considers using Kokomi’s technique for the Shogun’s army, but decides against it.
Kokomi also has a voiceline about Sara where she talks about what a formidable opponent the general is. Kokomi states that Sara’s performance in battle is “admirable” despite her lack of strategy.
In Kokomi's story quest, Kokomi goes to talk about peace with Kujou Sara, where they greet each other and Sara points out that Kokomi dealt her forces a devastating blow. Sara questions why the traveler is here, to which they respond that they are simply overseeing the exchange, and Kokomi agrees. Sara accepts the reasonable answer and the two continue with their peace talks. The negotiations move smoothly until Sara mentions something that ticks off one of the Watatsumi soldiers who shouts about the Kujou working with the Fatui. The soldiers on either side arm up and charge before the traveler gets in the middle, momentarily pausing the fight. Kokomi and Sara look at each other and seem to agree on something silently, as Kokomi then takes a seat and her soldiers lower their spears. Sara then proceeds to question two of her guards who were acting suspiciously when the Watatsumi island made the claim. They admit they talked a bit with the Fatui, and try to justify it, but Sara cuts them off.
Sara then turns back to Kokomi and apologizes, asking for another chance to continue the peace talks. Kokomi giggles and agrees, saying "I have every confidence in your ability to resolve this situation". The rest of the negotiations are cleaned up smoothly.
Once they are over, Sara says "I never knew the grand strategist of Watatsumi Island was a skilled negotiator as well as a formidable commander". Sara then says that she hopes that the next time they meet again, they can continue having civilized discussions as opposed to fighting out their differences on a battlefield. Kokomi gives Sara some advice about dealing with the Fatui, and Sara thanks her before leaving.
- “She is more proficient as a military strategist than a priestess. The way she uses directives to wage war is almost unheard of. I wonder if I should adopt this technique for commanding the Shogun's Army? Hmm... but this could lead us to a situation whereby war is waged at the negotiation table, each side with their pack of strategy cards, playing them one by one until a victor emerges... Then again, perhaps not. ”
- — Sara's voiceline about Kokomi
- “Mmm... I must admit, Kujou Sara is an opponent that cannot be taken lightly. She seldoms employ cunning stragedy, but her performance in open warfare is always admirable. The Shogun's Army places great trust in her abilities — they are united and ready to fight valianty under her command, even to death. Her forces have been a serious threat to the resistance on multiple occasions.”
- — Kokomi's voiceline about Sara
The official reveal of both characters in the Inazuma trailer is what led to them being shipped. This was mainly due to the popularity of the enemies-to-lovers trope and the two characters’ canon rivalry. Some people began making fanart for KokoSara, which attracted more fans to the pairing. Many fans seem to like these two because of their opposing sides on the war, which creates a lot of angst potential. Shippers portray them secretly pining for each other from opposing sides of the battlefield; looking at each other over a land of carnage and suffering that neither are able to cross due to their own responsibilities and positions chaining them in place.
The ship dynamic in fics and art involves Sara showing Kokomi a soft side when they're alone, in contrast to her usual serious personality. Their color combination is very pleasing as well, so many great works of fanart have been created depicting these two. The content varies between fluffy and angsty situations. Their height difference is also part of the ship’s appeal, with Sara being the tallest female character in game and Kokomi being on the shorter side.
For Sara, this ship is not as popular as EiSara, but still manages to hold on to its second place for her. Some EiMiko shippers may pair Sara with Kokomi. Unlike Sara, Kokomi is not a very popular character for shipping. KokoSara is currently rivaled only by Kokorou, Kazukoko and IttoSara.
On AO3, KokoSara currently has about 100 works.