Marichu is actually a basque name. The region is found between the French and Spanish border. Its the oldest indoeuropean language and culture of Europe. When Spain was a world power it sent its ships to south america and the philippines. Later migrations came to south and central america during the carlist and civil war.
Marichu is Maria and is one of the most common names there. If you look at Basque mythology Mari was the goddess of the land.