My Friend's Little Sister Has It In For Me! Novel Volume 1 was written by mikawaghost and illustrated by tomari.

If a girl teases you, that means she likes you!

Unfortunately, Akiteru knows from experience that isn’t the case. Because every girl he interacts with shows him nothing but scorn, and he’s not scored a single date from it! Luckily, he’s more concerned with securing a spot for him and his game-development buddies at his uncle’s business.

But when his uncle throws him a condition that involves playing the part of his daughter’s boyfriend, Akiteru has no choice but to take it. What will his best friend’s sister Iroha, who bullies him relentlessly, think of the news?

My Friend's Little Sister Has It In For Me! Novel Volume 2 was written by mikawaghost and illustrated by tomari.

Akiteru’s intent on living life optimally. Ever since Mashiro's shocking revelation, ups become downs and nothing’s as it seems! His friend’s little sister went from Annoying with a capital A to Sweet with a capital S, Mashiro's grown colder when Akiteru thought she was at her limit, his group’s scriptwriter has suddenly swapped genres, and even Murasaki Shikibu is sticking to deadlines! What’s it all mean?! And how’s Akiteru supposed to stay efficient in this topsy-turvy new reality?

My Friend's Little Sister Has It In For Me! Novel Volume 3 was written by mikawaghost and illustrated by tomari.

For any high schooler, summer vacation’s a time to let loose and have some fun! But for the ill-fated Akiteru, it just means stress, stress, and even more stress! As if his fake relationship with Mashiro wasn’t enough, Sumire’s dropped a tremendous bombshell on him, Iroha’s back to teasing him with redoubled effort, and now Midori’s acting mighty suspect too. Will Akiteru make it through the summer with his sanity intact? Or will this fiendish web of relationships finally spell his doom?

My Friend's Little Sister Has It In For Me! Novel Volume 4 was written by mikawaghost and illustrated by tomari.

Mashiro has just shared a devastating secret with Sumire.

Aki and Iroha have been forced through a ceremony that historically guarantees the participants will be married.

Meanwhile, Sumire is on the brink of freedom—but just what will she do with it?

So much for Aki’s efficient summer plans! Worse, he finds out the foundations beneath his Alliance are pillars of salt and sand.

With the Alliance pulled in all directions, will it even last the summer, or will it sink into the depths of the ocean?