"August 20, Part 1" (八月二十日① Hachi-gatsu Hatsuka ①?) is the 31st chapter of the Toaru Kagaku no Railgun manga series, released on May 27, 2010.
The chapter opens with Kamijou Touma losing 2000 yen to a faulty vending machine. Misaka Mikoto gently pushes him out of the way, as she wants a drink for herself. Touma, due to suffering amnesia in between this and their last meeting, doesn't recognize her, causing her to ineffectually attack him. Mikoto then kicks the vending machine to make it eject a drink.
Elsewhere, Uiharu Kazari and Saten Ruiko happen to meet a despairing Shirai Kuroko. Kuroko explains how Mikoto has been troubled lately but hasn't said anything to her. Saten suggests that Mikoto's strange behavior is due to a boy. The girls let their imaginations run wild with the reason behind Mikoto's late returns to her dorms. Suddenly, they hear an alarm from a vending machine and Kuroko teleports there to investigate. She sees the vending machine, smoking and surrounded by security robots, and deduces that Mikoto was here.
At this moment, Touma is running away from the vending machine (to avoid being caught up in Mikoto's theft) while Mikoto is chasing him with an armful of drink cans. They eventually stop and sit on a park bench, with Touma accepting a can. Mikoto talks about the fights they had previously, confusing Touma. Kuroko arrives and she mistakenly concludes (from seeing Touma and Mikoto together) that Saten's suggestion was correct. Introducing herself as Mikoto's "one and only partner", she makes a snide remark about Touma being easily attracted to other women, causing a flustered Mikoto to lash out with electricity. Kuroko teleports away, seeing that Mikoto is once again in lively spirits.
Just after Kuroko leaves, Misaka 10031 approaches the two from behind, mortifying Mikoto. Misaka 10031 criticizes Mikoto for committing theft. Mikoto pulls her away from Touma and questions her about the project's status, to which Misaka 10031 replies that it is continuing. Mikoto is shocked, feeling guilty about the death of the sisters and recalling the last one that died in front of her. Misaka 10031 tries to show her a cute kitten, but this only causes Mikoto to shout at Misaka 10031 to stop appearing before her. Misaka 10031 looks shocked and walks away, following Mikoto's instructions. Mikoto weakly calls out for her and the chapter ends with Mikoto semi-collapsed on the light-pole, in a state of despair.
- Touma is officially reintroduced to Misaka Mikoto after losing his memories.
- Parts of chapter adapted from Toaru Majutsu no Index Light Novel Volume 03 Chapter 1 Part 1-2
By order of appearance:
- Kamijou Touma
- Misaka Mikoto
- Saten Ruiko
- Uiharu Kazari
- Judgment Boy (cameo)
- Twin Tails Girl (cameo)
- Shirai Kuroko
- Electromaster - Misaka 10031
- Mikoto and Touma's first meeting is referenced by Mikoto, as well as their fight in the artificial riverbank.
- In the background while Saten Ruiko and Uiharu Kazari walk by a shop, the unnamed Judgment Boy and the Twin Tails Girl he saved back in Chapter 4 of Toaru Kagaku no Railgun are seen together in casual cloths on a date.
- In Japan, 2000 yen notes are actually exceedingly rare. When introduced on July 17, 2000 to commemorate both the new millennium and the G8 summit held in Okinawa, the 2000 yen note was the first Japanese denomination to have a primary numeral that was not 1 or 5. Though still in circulation, the 2000 yen note never caught on, partly because of this unusual distinction (to Japanese eyes) and the fact that many vending machines won't accept them. It could be said that, when Touma fed the machine with that bill, he was probably tempting fate.