A Filipino woman and a Japanese man were arrested Tuesday on suspicion of submitting a false birth certificate for her son to acquire Japanese citizenship, the Metropolitan Police Department said Thursday.

Marissa Floures Ito, 31, unemployed, and Michio Uchino, 55, a ramen shop owner, are suspected of conspiring to submit a birth certificate that wrongfully states that Uchino is the father of Ito's son to Ushiku City Hall, Ibaraki Prefecture, on April 21, the police said.

The arrest is the first of its kind since the Nationality Law was revised in January to allow children born out of wedlock to foreign women to obtain Japanese nationality if the Japanese father recognizes them as his.