It’s easy to get lost in the world of Jason Shiga. Readers must choose between storylines to follow in his comic adventure book “Meanwhile,” in a journey that will dead-end, finish in doom or end in happiness. There are thousands of branches to follow. The reader quickly becomes immersed in moving along story lines, making choices and restarting the story in an attempt to reach the final destination. The story builds upon itself as the reader journeys through the maze. The story plots are simple but intriguing: choose between time travel, the memory transfer helmet or the doomsday machine. “There’s one central mystery that you’re trying to solve,” Shiga said. It may take hours. Warwick’s Books in La Jolla invited comic-book artist Shiga, who lives in Oakland, to teach children how to make their own comic-book adventure on April 6. Warwick’s holds free events for children throughout the month. “Meanwhile” is equally engaging for children and adults. The book acts like a video game in that it’s accessible, active and can be obsessive. It’s brain stimulation in analytical reasoning and problem solving. “The overall point is to introduce children to science fiction concepts in a fun way,” Shiga said. Shiga was teaching a college class on comic books as literature 13 years ago when he decided to follow the footsteps of comic-book icon Adrian Tomine. “If he can do it, why not me?” Shiga asked himself one day. So, Shiga wrote the comic book, photocopied it and sold it to bookstores. “The advantage to the medium is that it’s really accessible to the average person,” Shiga said. “All you need is pen and paper and a photocopy machine.” Ten years later, Shiga’s work caught a publisher’s eye. Shiga has since authored 20 comic books, invented three board games, two card tricks, the greedy mug and bus clock.