Today, a two-year study ended, proving that normal sexual relations between pregnant Nekovalkyrja and other nekos and Geshrin is neither harmful to the mother neko nor the youngling. The study was originally intended to last only one year, but was extended because the participants volunteered to continue even with reduced compensation (they liked the humping).
A neko can become pregnant at any time, providing that her body has reproductive features enabled and she is in a "motherly mood," which is frequent thinking about reproduction and taking on nesting habits. Once an NH-12 youngling is grown inside the mother neko's womb, she can either remain inactive until the mother feels the time is right to give birth, or she can be activated and stay inside under support of the mother. Some nekos insert non-youngling NH-12s into themselves and use them as personal assistants.