For anyone confused about the exchange on page 17.
Souta offers the MC a pile of "Shiitake no Yama" then tries to offer him a pile of "Maitake no Sato" after seeing his hesitation.
These are parodies of two types of chocolate covered cookies in Japan called "Kinoko no Yama" and "Takenoko no Sato".
Which one is better is often a subject of discussion among some. Kinoko no Yama has more chocolate than cookie and Takenoko no Sato has more cookie than chocolate. It's kinda equivalent to the Coke vs. Pepsi debate, except both Kinoko no Yama and Takenoko no Sato are made by the same company, Meiji.