Identifying meaningful document fragments is a major advantage achieved by encoding documents in XML. In scholarly articles, such document fragments include sections, subsections and paragraphs. XML information retrieval systems need to search document fragments relevant to queries from a set of XML documents in a digital library. We present Kikori-KS, an effective and efficient XML information retrieval system for scholartic articles. Kikori-KS accepts a set of keywords as a query. This form of query is simple yet useful because users are not required to understand XML query languages or XML schema. To meet practical demands for searching relevant fragments in scholartic articles, we have developed a user-friendly interface for displaying search results. Kikori-KS was implemented on top of a relational XML database system developed by our group. By carefully designing the database schema, Kikori-KS handles a huge number of document fragments efficiently. Our experiments using INEX test collection show that Kikori-KS achieved an acceptable search time and with relatively high precision.