Headscratchers / Restaurant to Another World

• Since Alphonse (the shipwrecked sailor) clearly had seen members of his continent before in the restaurant, couldn't he have asked them for an SOS long before he was randomly found by a trading ship? You could argue that he was shipwrecked so far off course it would be difficult to locate him, but surely there would be some sort of ability to navigate using the position of the stars?
  • It's possible the journey was simply too dangerous to undertake, even to rescue Alphonse. No one else would have hard evidence of the man being alive, due to all the secrecy about the door, and it seems the area is both guarded by the kraken and prone to violent storms. As impressive and brave Alphonse was, he still ultimately was just one naval commander of the hundreds of others the kingdom had.
    • When exiting the restaurant, the location depends on the person opening the door. Couldn't Alphonse just follow one of the customers out to escape the island?
    • There is a scene in the light novel where two customers leave at the same time, they could see each other until they went through the door, once they went through the door they were transported back to their original door. Its probably a safety measure on the magic to prevent people from getting lost in completely different countries by mistake.
• From what I understand the customers from the restaurant pay using their world's currency but doesn't that mean many any ingredients used are not actually paid for since The Master can't use those coins to buy more ingredients. I know he gives the proceeds to the Alfade company but how is the restaurant still open if he can't break even at the end of the week.
  • Maybe The Master melts the gold coins and silver coins and sells them at precious metals exchange in his world. A 10 gram gold coin could easily fetch 50000 yen. The bag of gold from Alphonse Flugel alone could keep the restaurant running for years.
  • Also, The Master could have used the ingredients from Alfade company to make exotic dishes for normal Japanese customers. That way, the restaurant requires fewer ingredients on normal days (the other 6 days).
    • The restaurant eats the costs for the day. The ingredients bought from the Alphonse Company are eaten solely by the master for research.