Manga Like Ichinose-kun wa Itsumo Iinari.

The Ichinose family has served to protect the Saionji family since long ago. Until now, Kimihito Saionji and Takeru Ichinose have been glued at the hip as master and servant. Kimihito's haughty personality is an eyesore to his classmates. Still, as a master, he has to put on airs, no matter how much he wants to openly admire Takeru's coolness as well. On the other hand, Takeru doesn't mind being ordered around at all. In truth, his master is quite naive and helpless without a servant—and Takeru fully intends to keep it that way. He can abide by whatever command if it means having this unique side of Kimihito all to himself. (Source: MAL Rewrite)