A new class of higher-spin gauge theories associated with various Coxeter groups is proposed. The emphasize is on the $B_p$--models. The multi-particle $B_2$--higher-spin theory is conjectured to be associated with String Theory. $B_p$--higher-spin models with $p>2$ are anticipated to be dual to the rank-$p$ boundary tensor sigma-models. $B_p$ higher-spin models with $p\geq 2$ possess two coupling constants responsible for higher-spin interactions in $AdS$ background and stringy/tensor effects, respectively. Consistency of the holographic interpretation of the boundary matrix-like model in the $B_2$-HS model is shown to demand $N\geq 4$ SUSY, suggesting duality with the $N=4$ SYM upon spontaneous breaking of HS symmetries.