What was the only part of the US mainland attacked by the Japanese in World war 2?

Alaska, specifically Attu & Kiska islands which are in the western Aleutian Islands. Japanese troops landed on these islands in June 1942. These islands were retaken by US & Canadian troops in 1943.

The Japanese attacked Hawaiian military bases, but did not invade.

The Japanese invaded & seized Guam & Wake Islands in 1941. Guam is a US Territory, and Wake is a US possession.

The Japanese invaded & seized the Philippines Islands which was a US Territory during the war, that is now an independent nation.