“Time is the most important thing right now,” says Takako Yamaguchi. The artist, who at 72 is having her first institutional show with MOCA, suggests she has a limited number of active, working years. But this realization doesn’t bring her down; instead, she’s been having the most fun she’s ever had. Her mind is clearer than when she was in her 20s, and she is eager to paint every day, all day, in a white-walled room, on the second floor of a gray-blue apartment building in Santa Monica. Minutes into sitting in our wheely chairs beside her drafting table, it becomes clear that Yamaguchi’s preoccupation with time points back to her parents — her mother is going to be 96, and her father just turned 100. She is prepared to take a plane to Okayama, Japan, where they live and where she was born, at a moment’s notice. Over the last few years, she’s been gradually bringing objects from her parents’ home to Los Angeles, like ceramics, and has most recently been debating what to …