It was lesson time.
"Strictly speaking, Shikotsumyaku is a hereditary genetic disorder in our clan," Ryūshiki said. "The gene that suppresses osteoclasts is missing, so clan members with this condition often die young, before they even reach a hundred..."
"But you and I are among the lucky ones. We have auspicious power protecting us, which cancels out that side effect."
Kaguya looked herself over. "Shikotsumyaku... do I really have it?"
Ryūshiki smiled. "Yes. Your skin has the same unusual grayish-white color as mine."
"The other clan members are very pale too," Kaguya said.
"All right, I was just complimenting your fair skin," Ryūshiki said. "Anyway, I'm certain you have Shikotsumyaku. Come on, try channeling chakra into your bones like this..."
Shhk, shhk, shhk...!
It was the sound of bones piercing flesh.
"..." Ryūshiki reached behind his neck, gripped the end of the spine protruding there, and pulled the entire thing out.
"Come on, give it a try..."
"Mm..." Kaguya strained for ages, trembling all over, but she simply couldn't do it.
"That shouldn't be happening..." Ryūshiki muttered, rubbing his chin. Then realization struck him. "Oh! I get it... you're afraid it'll hurt, aren't you?"
"I-I'm not..." Kaguya hastily said.
She steeled herself and channeled chakra into her bones, but the moment a tiny bone sprout emerged, tears spilled from her eyes despite herself.
Ryūshiki sounded helpless. "You're such a scaredy-cat, yet you dared to snap off your own horns. You really are something..."
"..." Kaguya felt wronged.
"I really don't know what to do with you." Ryūshiki stood, walked behind Kaguya, and gently parted the hair at the back of her head.
"!" Kaguya shuddered.
"Don't move," Ryūshiki said softly. "I'll help you..."
He touched the tip of his index finger to the back of Kaguya's neck.
"All right," Ryūshiki