We present the first complete model of Littlest Modular Seesaw, based on two right-handed neutrinos, within framework multiple modular symmetries, justifying use moduli fields which take their values at 3 specific stabilizers $\Gamma_4 \simeq S_4$, including a new phenomenological possibility. Using semi-analytical approach, we perform $\chi^2$ analysis each case and show that good agreement wi...