After the fall of Osaka Castle in 1615 the Shogun gave the property that is now Sanshiro Pond to the Maeda family. Maeda Toshitsune, the richest daimyo outside the Tokugawa family, was know for his lavish lifestyle and worked on the beautification of the pond and the garden around it. When he died, Maeda Tsunanori, the fifth lord in the Maeda family, continued his work on the garden, making it renowned as the most beautiful garden in all of Edo.
The garden was then called "Iku Toku En" or "Garden of the Teaching of Virtue". The garden was designed with eight borders and it had eight differently designed landscapes, with manmade hills, pavilions, and of course a pond.
The outline of the pond was designed in the shape of the Chinese character "Kokoro or Shin", which means heart and then it received the official name "Iku Toku En Shin-ji-ike" or "Garden of the Teaching of Virtue with the "Kororo" shaped pond".
When Natsume Soeseki wrote about this pond in his book, it became widely known as Sanshiro Pond after the title of his book.