"Strange Coincidence" (奇縁 Kien?) is the 80th chapter of the Toaru Kagaku no Railgun manga series, released on October 27, 2015.
On a day in September, Ruiko is grocery shopping for some canned mackerel and after buying the last two cans a little blond girl is horrified that the store has run out. Ruiko, seeing her, tells her that she bought them because she saw a special on TV that says that it good for their looks. Frenda had none of that and demands to have the canned mackerel from her, so much so that Frenda follows Ruiko as she goes home. Frenda then tells that she will trade her for the cans, seeing as she only has her card with her, though her doll and missile, both of which she lies about its true purpose, is a miss to Ruiko. Ruiko then asks if Frenda really likes canned mackerel to which she espouses how she not only needs it, but has supported the industry and that people like Ruiko shouldn't have them because they saw it on TV.
With a sigh, Ruiko finally gives in and hands Frenda one can of canned mackerel, much to Frenda's delight, and with not a moment to lose, starts opening it to eat it on the spot in the middle of the sidewalk. However, Frenda opens it up with one of her igniters and it suddenly explodes before her, ruining her can of mackerel. Ruiko starts walking away but Frenda begs her to reconsider. Ruiko however, wants the can of mackerel for dinner and is angry with Frenda for wasting food. Frenda pretends to cry to get her sympathy but Ruiko ignores her. Finally, after some whining from Frenda, Ruiko finally invites her to dinner at her place.
At first, Frenda is dismissive of mixing mackerel with curry but immediately changes her mind after tasting Ruiko's cooking. Before leaving, Frenda compliments Ruiko's cooking and asks her if she has the Speech Bubble app, giving her ID to Ruiko after she reveals she does so. And so, Ruiko and Frenda maintained contact with one another, exchanging news about their daily lives even up to the height of the Indian Poker fad.
One day, Ruiko visits the Indian Poker card peddler, who sells to her a new card from someone who can pick up small things using chopsticks. Little did she know that the Darkness of Academy City has begun to stir. The Girl in the dress contacts the Boy with goggles, regarding the recent Indian Poker trend, and how scientists and researchers are using it to backup themselves as a form of insurance. It is later revealed that information regarding the Tweezers may have been leaked in one of the cards. The girl of the dress tells the boy to begin searching for it, and as he narrows the information down it leads him to a certain message left by Saten Ruiko.
- During the month of September, Saten Ruiko encounters Frenda Seivelun while out grocery shopping, and later become friends with her.
No magic or esper abilities are featured this chapter.
- This chapter acts as a prologue for volume 15 of the Toaru Majutsu no Index light novel, showing the initial plans of SCHOOL before the beginning of the novel.
- The chapter references Frenda's later distaste of canned mackerel and her desire to eat curry as featured in volume 15 of the light novel.
- What exactly is Frenda's nationality?
- What do the Girl in the dress and the Boy with goggles want with the Tweezers?
- Frenda: "If I don't eat some for a while, I get really bad palpitations, my limbs start shaking, and I hallucinate."--to Ruiko regarding why she likes canned mackerel.
- Ruiko: "People who waste food do not deserve any sympathy."--to Frenda after she blew up her can of mackerel.