MisakaLovesYou
I think you might be interested in some of these!

A Certain Destined Introduction
By: Cun
"What's the big deal about Tokiwadai and its celebrities anyway? When Kuroko starts the prestigous middle school, she is determined to not get smitten by whatever fangirl virus runs around campus. With too much work at Judgment and an ongoing crime case to boot, there's no time for silly gossip. Too bad the Railgun is harder to resist than she thought."
Link: https://www.fanfiction.net/s/6373544/1/A-Certain-Destined-Introduction

A Certain Railgun Fan Fic
(Great title, huh? xD)
By: Cun
"Trouble starts brewing in Academy City when people are suddenly attacked all over the place; ending up in the middle of it as always, Mikoto, Kuroko and the other girls have to use their wits and their abilities to get rid of the problems."

A Certain Cliché Switchover
By: Cun
"Mikoto and Kuroko trade bodies and has to pass as each other while at school. From there, everything spirals downwards."
Link: https://www.fanfiction.net/s/7178946/1/A-Certain-Cliché-Switchover

A Certain Messy Predicament
By: Cun
"When Mikoto loses a treasured item, how will the joined forces of Touma and Kuroko save the day? Certainly not the way anyone else would..."
Link: https://www.fanfiction.net/s/7879974/1/A-Certain-Messy-Predicament

Big Sister's Responsibility
By: GreatSnapper
"Mysteries abound in Academy City, and once again Mikoto finds herself at the center of it all. This time though, she's determined not to simply stand by and let those she cares about suffer the consequences. Becoming strong enough to protect what is most important to her comes with its own set of complications though, and as usual, Mikoto hasn't really thought everything through."
Link: https://www.fanfiction.net/s/8769430/1/Big-Sister-s-Responsibility

A Certain Droll Hivemind
By: EarthScorpion
" 'No, no,' Misaka-11111 protests, with great concern in her voice. 'Do not read my secret diary. How is it even online? ' she asks, confusion mixing with her alarm. 'If someone were to read it, they would be able to understand my inner thoughts. That is not natural, completely unlike the perfectly normal operations of the Network. Please,' Misaka begs, 'do not read it.' "
Link: https://www.fanfiction.net/s/9805735/1/A-Certain-Droll-Hivemind

A Certain Technological Annihilaser
By: Fifteen1413
"For Hikaru, a ten year old level-2 child error, the thought of becoming a hero never really held much appeal. However, when her friends end up the target of deadly attacks, she reluctantly becomes Academy City's youngest vigilante. Armed only with the ability to make blue light, Hikaru is forced to be creative to get the edge she needs."
Link: https://www.fanfiction.net/s/11552805/1/A-Certain-Technological-Annihilaser

In Memoriam
By: Shocksz
"AU/Rewrite. In a city where science has made the impossible mundane, a young man meets a very strange girl, who speaks to him of things yet stranger. Meanwhile, four friends stumble into a conspiracy that threatens to overturn everything they thought they knew about their home."
Link: https://www.fanfiction.net/s/9442823/1/In-Memoriam