First of all tell me a little about your series and introduce us to the sequel(s).
Hey there! My series is called Yokai Calling and it’s a YA epic fantasy about three exceptional teenagers and their quest to unravel the mysteries of their clan histories and prevent the rise of an ancient evil. Hidekazu, a stubborn-to-a-fault prodigy mage; Aihi, a spoiled but exceptionally loyal princess; and Masanori, a talented engineer who wishes he was a warrior. Secrets, betrayals, and circumstance throw them on separate paths that intertwine–sometimes in opposition–in a braided narrative that will ultimately decide the fate of their homeland. 
The series begins with Spirit of the Dragon, where Hidekazu, Aihi, and Masanori work together to solve a mystery and rescue their kidnapped friends and stop a wicked sorcerer. However in the sequel, The Dragon’s Eye, the trio’s relationship is strained while they seek to unlock the power of an ancient artifact–a Dragon Eye–to stop the plans the sorcerer set in motion. A Dragon’s Curse is about the aftermath of their interactions with the artifact and the curse that’s unleashed on one member of the group, and the series of events that permanently fractures them. Finally, Blood of Dragons is the conclusion to the series, where war against a rival nation and the monsters they’ve been trying to stop force Hidekazu, Aihi, and Masanori together again for their last chance to protect their loved ones.
Along the way, they face demons, spirits, and dragons, but ultimately nothing is as dangerous as the darkness within themselves. The Yokai Calling series thematically deals with how ambition at the cost of your mental health can bring rise to the demons hiding within you. The series is for fans of Avatar: The Last Airbender and Japanese mythology & folklore who like a darker touch to their stories.

Do you find that most of your readers continue to read the whole series? Why do you think that is?  
I don’t have a super high readthrough rate like some authors do, but I find that the readers who really connect with my characters and the story themes end up reading the whole series. From what I’ve gathered by talking to my readers, it’s the world and characters that keep them reading.

How difficult is it to add new characters in a sequel into already established relationships? 
I don’t find it very difficult at all. Because my books are written from 3 POVs already, each main character has their lens into the world and the nature of the plot–which often has the characters moving around the world–means they are meeting new characters independently of each other all the time. 
The trick is, for me, to have the new characters who are added be relevant to the story or to the characters’ developmental arcs. I find it much harder to add characters who end up just being background flavour, because they don’t feel as natural.

Is it difficult to continue with worldbuilding for a world you have already built in book 1?  Do you find it easier to switch locations for the sequel and start again with worldbuilding? 
In a way it’s more difficult because you already have an established set of rules and descriptions in your earlier books that you need to follow when writing sequels. However, depending on the circumstances, it can either be liberating to take a break from those already established environments and just create something new with fewer limitations, or it can be quicker and easier to write somewhere that’s familiar. I don’t normally choose settings based on this though, I always pick what seems best for the story regardless of if it makes the writing easier or harder for me.

Have you ever been stymied by a worldbuilding or plot detail from book 1 that is very inconvenient to deal with or write your way around in subsequent books? 
Oh you know it, lol. Spirit of the Dragon, the first book in my series, was my first published book and I had a lot of grand plans for the series and laid a lot of the foundation in that book… but in all that planning I made one fatal flaw that caused a domino effect of larger issues with the rest of the series. It has to do with what happens to the villain at the end of book 1… so I juggled those issues throughout the remainder of the series because there was no way around it unless I went back to rewrite the end of the book. 
It might have been easier if I’d done exactly that, but I didn’t think about that until after I wrote book 3, I believe, so it was a little late by then.

Would you say your craft has improved with the subsequent books?
Absolutely, without a doubt, to the point that after I finished book 4, I decided to go back through the books and create significantly updated editions of the series before creating the omnibus edition. Even after all that, I still think book 1 in my series is the weakest and I really grew into myself as a writer in books 3 and 4 in the Yokai Calling series.

Do you have all the timeline planned for the full series?
All of the books in the Yokai Calling series are written and published already! Although there are many more books planned for this world still and for later on in the lives of my main characters, there isn’t a concrete timeline on that yet.

Do you have any marketing tips for sequels?
It’s really hard! I would say that I’m still struggling with it despite my whole series being out. I’ve primarily focused on marketing either the first in series and relying on that to bring readthrough, or marketing the series together through the omnibus. I throw the other books out there on social media, my newsletter, or on promo sites every now and then to try and get them in front of readers who might have already read book 1.