Aikotoba -Silver Snow Sister-

Hoshitsugu Kotetsu and Hoshitsugu Shirone are non-blood-related siblings.

The younger sister Shirone, is an athlete. Her talents in figure skating, smooth skin, and hair that is brighter than snow, earn her the nickname Snow Fairy (Fee des Neiges), her reputation in her hometown Sendai, is spreading.

On the other hand, the older brother Kotetsu, is unknown...... If anything, he has a bad reputation as well. Although it is a misunderstanding for the most part, the fact that his blonde hair makes him intimidating is undeniable, the positions of the siblings are entirely opposite​. One day, in order to deliver something that Shirone forgets, Kotetsu heads to the skating rink, however......

"Nii-san should leave me alone. How about getting a girlfriend?"
"That's a good idea."

Taking his sister words seriously, Kotetsu uses a popular online app "Aikotoba". He gets an 88.88% rate of successfully matching with other partners. But, what comes after is something unexpected......?

Meanwhile, the obsession with the matchmaking app, and the never-seen-before mysterious enthusiasm of Kotetsu, make Shirone feels unpleasant.

"If Nii-san is let loose​ like this,
the peace of this town might be threatened!"

Using such thoughts as an excuse, Shirone comes up with a proposal.

"Unpopular loser...... For Nii-san who is a beginner in love,
the ABCs of love, let's learn from the first character."

Thus begins a love lesson......? Starts with a three months deadline, not enough explanation, but they understand each other.

"Don't worry, Nii-san. Shirone will take responsibility...... Ah.
By responsibility, that's not what I meant, alright."
"What you meant is?"
"Please die, pervert."

Will Shirone guide her brother to become capable of love, and will Kotetsu be able to leave his sister?