Does Reito just... forget he has access to an omniscient goddess in his head? I can kinda buy her not telling him everything because of.... well something (the most we've gotten so far is him interfering with others makes it so she doesn't know their future), but why the heck would he not ask her where the mother is/Kotomin's original home immediately after empathizing with her sad back story of being lost? This just makes the MC seem either stupid or heartless. Also, why did the goddess tell him. If we're going off of that her plan from the start was to endear the MC in Kotomin's eyes (netting him an ally and rare item at once) then she also understood that by doing that she'd alter Kotomin's life in a way that she can no longer clearly she her future (i.e. she willing made it unclear for her if Kotomin every finds her mother), so she also comes off heartless by not reassuring the MC they'd help her find her mom later or having him tell the location of Kotomin's home to her straight away.