Sinthusa natsumiae is a butterfly of the Lycaenidae family. It is endemic to the Philippines and found on many islands. It is very beautiful, especially on the forewing upperside of male it has two different brilliant blue colours. Forewing length is about 12-15 mm. It flies fast and sometimes flies downward.
Hayashi, Hisakazu, 1979: New Lycaenid Butterflies from Mindanao, the Philippines. Tyô to Ga. 30(1,2): 83-90. 
Treadaway, C. G., 1995. Checklist of the butterflies of the Philippine Islands (Lepidoptera: Rhopalocera) Nachrichten des Entomologischen Vereins Apollo Suppl.14: 7-118.
Takanami, Y. & Seki, Y., 2001. A synonymic list of Lycaenidae from the Philippines. Edn. 12.
Treadaway, Colin G. & Schrőder, Heinz G., 2012: Revised checklist of the butterflies of the Philippine Islands (Lepidoptera: Rhopalocera). Nachrichten des Entomologischen Vereins Apollo, Suppl. 20: 1-64.