HSQLDB / PHP / Tomcat 8 / Quercus - Insert non-English chars

Question

INSERT INTO words (word, meaning) VALUES ('Цветок', 'Flower')

When I execute this SQL statement from an SQL client (DbVisualizer), the values in the table look exactly like you see them here in the statement, i.e. Цветок is not encoded.

When I execute it from PHP over Tomcat 8 / Java version "1.8.0_101" (Quercus 4.0.39) , the values in the table are encoded exactly as if I would run the PHP urlencode() on them. So Flower is not changed, but Цветок is - now it looks in the table through the SQL client like ЦвеÑок

Why is there difference between running the SQL statement from the client or from PHP?

How can I insert this data from PHP so that it will be saved in the database unchanged?

UPDATE

Here is my Tomcat context.xml HSQLDB Resource:

  <Resource name="jdbc/mydb" auth="Container" type="javax.sql.DataSource"
               maxActive="100" maxIdle="30" maxWait="10000"
               username="me" password="kjsfhsjhfsd" driverClassName="org.hsqldb.jdbc.JDBCDriver"
               url="jdbc:hsqldb:hsql://localhost:9001/mydb?characterEncoding=UTF-8"/>

The characterEncoding=UTF-8 is actually MySql specific (so having it breaks this resource!). What is the HSQLDB equivalent? I could not find...

I also tried to set the php.ini with unicode.semantics=on as explained here:

http://www.caucho.com/resin-3.1/doc/quercus.xtp#php.ini

http://www.caucho.com/resin-3.1/doc/quercus.xtp#Internationalization-16-bitunicode

http://www.caucho.com/resin-3.1/doc/quercus.xtp#encoding

However, it did not make any change...