Konosuba OVA

Blessings On This Wonderful Choker! (このらしいチョーカーにを！, Kono Subarashii Chookaa ni Shukufuku wo!) is a special OVA episode of the Konosuba anime, bundled with the ninth volume of the light novel.

Summary

 * note: this takes place after episode 12 where Kazuma mentions not knowing who Yunyun is

While running into Yunyun at Wiz's shop, Kazuma ends up putting on a choker that supposedly grants wishes. He quickly discovers, however, that this choker will gradually tighten and eventually strangle him to death in four days unless he can fulfill the wish he had subconsciously made while putting it on. Taking advantage of the pity he receives from the other girls as a result, Kazuma guilts them into following all kinds of ridiculous and perverted commands as they try to grant his unknown wish. At the end of the fourth day, Kazuma finds himself at peace after letting out all his callous feelings towards the girls; he told Megumin he tried to feel her breasts when he had to carry her after using explosion, Yunyun and Wiz he looks at their chest when he talks to them, Darkness that he started thinking of her as just breasts since she moved into the mansion, and Aqua no matter how hard he tried, he couldn't get turned on by her, upsetting her that he never thought of her like he does the others. It turns out the wish he had made was that he could have some peace and quiet which occurred before his confessions, resulting in the choker become undone without them knowing. Angered by the humiliation they were subjected to and the confessions, the girls quickly take their revenge on Kazuma, who once again finds himself in an awkward meeting with Eris.

Plot
Kazuma's party went to Wiz's shop to say hello and discovered Yunyun hiding behind one of the shelves. It turned out that Yunyun hangs out at Wiz's Shop quite frequently, in hope that she may run into Megumin "by chance." After Yunyun got caught, she tries to pretend that she is a regular shopper and randomly grabbed the wish-granting choker from the shelves. As Megumin and Yunyun argued, the choker fell from Yunyun's hand and landed near Kazuma, who tries to ignore the minor chaos broke out around him and picked up the choker.

Reading the description "This choker will grant any wish," Kazuma falsely believe it as a good-luck charm, and tries it on. Seeing this, Wiz soon told Kazuma about how the choker is a popular weight-loss tool among women and it forces the wearers to fulfill their own goals/wishes. The choker cannot be taken off by force and will gradually tighten to the point that it may kill the wearer in 4 days unless the he/she fulfill the stated goal in time.

Kazuma cannot remember what he wished for, so the ladies decided to help Kazuma by fulfilling any wishes he can think of, in order to save his life. They quickly learned that Kazuma's wishes are obnoxious and are all borderline sexual embarrassments, but they have no choice except to go along with his demands. The ladies went along with Kazuma's every wish despite their misgivings, but none of those is Kazuma's actual wish and the choker gradually tightens.

On the last day, Kazuma resigned to his fate and made peace. After the group hugged each other, the viewers can hear an audible click sound. No one noticed that the choker had been unlocked though, and Kazuma preceded to deliver his unflattering "apologies" to each of the ladies. All of those apologies are basically the honest but deeply offensive opinions Kazuma had. As Aqua shook Kazuma for his comments about her, they finally discovered the choker had already been unlocked. Kazuma then realizes that his true wish was to have some peace and quiet, and that was fulfilled at the last moment.

As Aqua picked up the choker and "invited" Kazuma to try on the choker again, he reflected on his own words and his actions over the past days. The OVA ended with Kazuma sitting in Eris' reincarnation room, implying that he was either killed by the ladies directly or didn't survive his second try with the "wish-granting" choker.

Timeline paradox?
Being an OVA, the episode clearly doesn't takes place before season 2. The crew already knew who Yunyun was so it must have taken place after season 2 episode 2. The whole party was present so it must've also taken place after season 2 episode 3 as Darkness was absent before then. Season 2 episode 4 takes place immediately after episode 3, so it couldn’t have occurred between them. The party’s debt was also mentioned which meant the episode must have been before season 2 episode 5 where the group's whole debt was paid off Since season 2 episode 4 was immediately followed by season 2 episode 5, the OVA couldn't have took place in between. Vanir II isn’t present at Wiz’s store, and it’s implied that the party met Vanir II the first time they visited Wiz after the original Vanir’s defeat (to inform her of his “death”) The only possibility was that the OVA was after their battle with Vanir but before the award ceremony, which for some reasons took a few days to announce; that would've been unlikely as such a big achievement should be announced immediately but this is so far the only plausible time in which this episode could take place.

Characters

 * Satou Kazuma
 * Aqua
 * Megumin
 * Darkness
 * Wiz
 * Yunyun
 * Eris