Books in the Wotakoi: Love is Hard For Otaku series in order

"After years of butting heads and petty disagreements, Hanako and Taro begin to realize that the next stage of their relationship may be the most challenging one yet. Naoya faces his own hurdles in trying to understand his feelings toward Ko, whose quest for personal growth has led her farther out of his reach. Fortunately, big brother Hirotaka has some insight to share on the topic, which may bring to light a new perspective of what Narumi means to him"--Provided by publisher.