Complex sentence: On April 14,2010, they released "Happy" which is one of singles to release consecutively for two weeks, and another single, "Mahō no Ryōri (Kimi kara Kimi e)" was released on April 21,2010.
Split into simpler sentences: On April 14,2010, they released "Happy" which is one of singles to release consecutively for two weeks. Another single, "Mahō no Ryōri (Kimi kara Kimi e)" was released on April 21,2010.