\documentclass[a6paper]{ltjsarticle}
%\documentclass[paper=b5j]{jlreq}
-\usepackage{luatexja-adjust}
+\usepackage{luatexja-adjust,amsmath}
\ltjenableadjust[profile]
\usepackage[pdfbox]{gentombow}
\begin{document}
+\baselineskip10pt
\noindent\makeatletter
\smash{\rlap{%
\kern\dimexpr-\oddsidemargin-1in-10mm%
\raisebox{\dimexpr-.5\paperheight+\headsep+\headheight+\topskip+\topmargin+1in}%
{\vrule height0mm depth.5\paperheight width 5pt\vrule height.5\paperheight depth 0mm width 5pt}%
}}%
-aiueo \strip@pt\dimexpr0.35145980351459803\paperheight mm%
+$\smash[t]{\displaystyle\int_{A_A}}$aiueo \strip@pt\dimexpr0.35145980351459803\paperheight mm\\
+ああああああああ$\displaystyle\int_{H_p}^{H^X}$dsadsadsad
+
+\newpage
+\noindent
+$\displaystyle\int_{A_A}$aiueofgfasd\\
+ああああああああ$\displaystyle\int_{H_p}^{H^X}$dsadsadsad
+
+\newpage
+\noindent
+$\displaystyle\int_{A_A}$aiueofgfasd\\
+ああああああああ$\displaystyle\int_{H_p}^{H^X}$dsadsadsad
+
+\newpage
+\noindent
+$\displaystyle\int_{A_A}$aiueofgfasd\\
+ああああああああ$\displaystyle\int_{H_p}^{H^X}$dsadsadsad
\end{document}