Forest Ranger, starting from Picking Up a Lynx Girl - Chapter 252 - : You’re not mistaken, the Lynx won?

When The Cute Kunoichis Spied on Their Teacher's Secret is a light novel written by Kazuma Kamachi and illustrated by Ryuushi Tajima.

The story takes place in a world where Japan never ended their isolationist phase, and agents from foreign powers are always threatening to steal the country's advanced technology. In order to combat this threat there has been a resurgence of ninjas that use Strategic Martial Arts, techniques that combine cutting-edge modern technology with a traditional foundation of martial arts and ninjutsu. The story follows Souha Sugiyado, a 17-year old ninja instructor and former ninja prodigy who was forced to retire from active duty by the wounds he suffered in his last mission. Souha's four students are all kunoichi who have all gained the rank of Elite Ninja, the highest official rank available to ninja. However, one day two Shogunate ninja approach him with the news that his four students have gone rogue and have stolen a portable modular nuclear reactor, and thus they ask for his help in bringing his students to justice.

In a peculiar twist of fate, Lee Taeok, found himself in an extraordinary predicament. Little did he know that his scathing critique of a popular novel, ridiculing its blatant naivety and overly innocent take on romance, would set in motion a perplexing chain of events, ultimately leading to his unexpected rebirth as the delinquent character, Baek Taeyang, from the very same novel.“You should have taken better care of your girlfriend.”In the world of the Academy Sweet Love Diary novel, Baek Taeyang is destined to “rescue” the heroines.

A very sweet entertainment circle novel about a closeted gong x fudanshi shou.

- Description from Novelupdates