AI380
I have checked your novel. A better cover would do a big difference. In the first chapters, i have seen many issues of verb tense consistencies. You either stick writing narrative with preterit or present, but not both at the same time in the same paragraph. It feels really weird and i think you lost quite a few readers because of this.
Some examples in first page of chapter 1:
First paragraph:
"The final day of summer break, at a random beach in Japan. A seventeen years old young man was walking along the beach. Looking to his face, he is a really good looking person with a 'rich boy look'. The boy's name is Seito Kenji, let's just call him Seito."
"was walking" should be followed by "he was", "the boy's name was"
If you choose to use present tense, then you have to use "is walking" instead.
Second paragraph:
"Seito stopped, he looked at the sea and most importantly the bikini girls, and his friends who were playing in the water. Then another girl with a T-Shirt and short pants walks toward him. Seito looks at the girl and he spoke"
Same issue. 1st paragraph ends with present tense, but you use preterit in this paragraph and once again ends with present tense.
If you keeps "stopped,looked at, were playing", then "walks toward" and "looks at" must become "walked toward" and "looked at".
I'm not an english native but it feels weird to read even for me because verb tense consistency exists in almost every language (if not all of them).
About the novel itself, you missed the visibility period brought by the 1st month in new ranking. So if i was you, i would first fix these issues then republish your novel again by deleting this one and creating another with almost the same name.