Master Clans Conference Chapter (II) is the 18th volume in the Mahouka Koukou no Rettousei Light Novel series.
Black Sage was behind the explosion at the end of Volume 17. The public starts to blame magicians for the bombing attack. (Heigu apparently used a corpse instead of a living person to infiltrate their meeting location). This ignites the return of the Anti-Magician propaganda. The Ten Master Clans decide that they need to get to the bottom of this. Tatsuya, Juumonji, Masaki and Mayumi team up to hunt down the Black Sage. Soon, Tatsuya and the others go ahead towards an unpredictable course/direction/way. When Tatsuya is near to grasping the clue leading to Heigu's whereabouts he is blocked by an unexpected opponent.
Gouki says to Masaki: The Yotsuba Clan's Shiba Tatsuya-dono is equal to you, he'll join to the search under Juumonji-dono's leadership. Masaki, show your will-power. Pushed by Gouki, Masaki tries something unexpected, he tries to get close to Miyuki while Mayumi is also being pushed to the forefront by various schemes not of her own. The battle begins before Valentine's Day. Meanwhile the emotional battle continues.